diff --git a/cmd/picoclaw/main.go b/cmd/picoclaw/main.go
index 10b53948b..7e9e252b6 100644
--- a/cmd/picoclaw/main.go
+++ b/cmd/picoclaw/main.go
@@ -120,6 +120,20 @@ func copyDirectory(src, dst string) error {
 }
 
 func main() {
+	parsedArgs, configOverride, err := parseGlobalFlags(os.Args)
+	if err != nil {
+		fmt.Printf("Error: %v\n", err)
+		os.Exit(1)
+	}
+
+	if configOverride != "" {
+		if err := os.Setenv(config.EnvPicoClawConfig, configOverride); err != nil {
+			fmt.Printf("Error setting %s: %v\n", config.EnvPicoClawConfig, err)
+			os.Exit(1)
+		}
+	}
+	os.Args = parsedArgs
+
 	if len(os.Args) < 2 {
 		printHelp()
 		os.Exit(1)
@@ -158,10 +172,9 @@ func main() {
 
 		workspace := cfg.WorkspacePath()
 		installer := skills.NewSkillInstaller(workspace)
-		// 获取全局配置目录和内置 skills 目录
-		globalDir := filepath.Dir(getConfigPath())
-		globalSkillsDir := filepath.Join(globalDir, "skills")
-		builtinSkillsDir := filepath.Join(globalDir, "picoclaw", "skills")
+		paths := config.ResolveRuntimePaths()
+		globalSkillsDir := paths.GlobalSkillsDir
+		builtinSkillsDir := filepath.Join(paths.HomeDir, "picoclaw", "skills")
 		skillsLoader := skills.NewSkillsLoader(workspace, globalSkillsDir, builtinSkillsDir)
 
 		switch subcommand {
@@ -200,9 +213,45 @@ func main() {
 	}
 }
 
+func parseGlobalFlags(args []string) ([]string, string, error) {
+	if len(args) == 0 {
+		return args, "", nil
+	}
+
+	filtered := make([]string, 0, len(args))
+	filtered = append(filtered, args[0])
+	var configOverride string
+
+	for i := 1; i < len(args); i++ {
+		arg := args[i]
+
+		switch {
+		case arg == "--config":
+			if i+1 >= len(args) || strings.TrimSpace(args[i+1]) == "" {
+				return nil, "", fmt.Errorf("--config requires a path")
+			}
+			configOverride = args[i+1]
+			i++
+		case strings.HasPrefix(arg, "--config="):
+			value := strings.TrimSpace(strings.TrimPrefix(arg, "--config="))
+			if value == "" {
+				return nil, "", fmt.Errorf("--config requires a path")
+			}
+			configOverride = value
+		default:
+			filtered = append(filtered, arg)
+		}
+	}
+
+	return filtered, configOverride, nil
+}
+
 func printHelp() {
 	fmt.Printf("%s picoclaw - Personal AI Assistant v%s\n\n", logo, version)
-	fmt.Println("Usage: picoclaw <command>")
+	fmt.Println("Usage: picoclaw [--config <path>] <command>")
+	fmt.Println()
+	fmt.Println("Global options:")
+	fmt.Println("  --config <path>    Use a custom config file path")
 	fmt.Println()
 	fmt.Println("Commands:")
 	fmt.Println("  onboard     Initialize picoclaw configuration and workspace")
@@ -983,8 +1032,7 @@ func authStatusCmd() {
 }
 
 func getConfigPath() string {
-	home, _ := os.UserHomeDir()
-	return filepath.Join(home, ".picoclaw", "config.json")
+	return config.ResolveRuntimePaths().ConfigPath
 }
 
 func setupCronTool(agentLoop *agent.AgentLoop, msgBus *bus.MessageBus, workspace string, restrict bool) *cron.CronService {
diff --git a/cmd/picoclaw/main_test.go b/cmd/picoclaw/main_test.go
new file mode 100644
index 000000000..5830d7c7f
--- /dev/null
+++ b/cmd/picoclaw/main_test.go
@@ -0,0 +1,70 @@
+package main
+
+import (
+	"reflect"
+	"testing"
+)
+
+func TestParseGlobalFlags_ConfigPair(t *testing.T) {
+	args := []string{"picoclaw", "--config", "/tmp/config.json", "gateway", "--debug"}
+
+	filtered, override, err := parseGlobalFlags(args)
+	if err != nil {
+		t.Fatalf("parseGlobalFlags() error: %v", err)
+	}
+	if override != "/tmp/config.json" {
+		t.Errorf("override = %q, want %q", override, "/tmp/config.json")
+	}
+
+	want := []string{"picoclaw", "gateway", "--debug"}
+	if !reflect.DeepEqual(filtered, want) {
+		t.Errorf("filtered args = %#v, want %#v", filtered, want)
+	}
+}
+
+func TestParseGlobalFlags_ConfigEqualsSyntax(t *testing.T) {
+	args := []string{"picoclaw", "--config=/tmp/config.json", "status"}
+
+	filtered, override, err := parseGlobalFlags(args)
+	if err != nil {
+		t.Fatalf("parseGlobalFlags() error: %v", err)
+	}
+	if override != "/tmp/config.json" {
+		t.Errorf("override = %q, want %q", override, "/tmp/config.json")
+	}
+
+	want := []string{"picoclaw", "status"}
+	if !reflect.DeepEqual(filtered, want) {
+		t.Errorf("filtered args = %#v, want %#v", filtered, want)
+	}
+}
+
+func TestParseGlobalFlags_MissingValue(t *testing.T) {
+	tests := [][]string{
+		{"picoclaw", "--config"},
+		{"picoclaw", "--config", ""},
+		{"picoclaw", "--config= "},
+	}
+
+	for _, tt := range tests {
+		_, _, err := parseGlobalFlags(tt)
+		if err == nil {
+			t.Errorf("parseGlobalFlags(%#v) expected error, got nil", tt)
+		}
+	}
+}
+
+func TestParseGlobalFlags_DoesNotConsumeCronShortFlag(t *testing.T) {
+	args := []string{"picoclaw", "cron", "add", "-c", "* * * * *"}
+
+	filtered, override, err := parseGlobalFlags(args)
+	if err != nil {
+		t.Fatalf("parseGlobalFlags() error: %v", err)
+	}
+	if override != "" {
+		t.Errorf("override = %q, want empty", override)
+	}
+	if !reflect.DeepEqual(filtered, args) {
+		t.Errorf("filtered args = %#v, want %#v", filtered, args)
+	}
+}
diff --git a/pkg/agent/context.go b/pkg/agent/context.go
index cf5ce2913..4025f8690 100644
--- a/pkg/agent/context.go
+++ b/pkg/agent/context.go
@@ -8,6 +8,7 @@ import (
 	"strings"
 	"time"
 
+	"github.com/sipeed/picoclaw/pkg/config"
 	"github.com/sipeed/picoclaw/pkg/logger"
 	"github.com/sipeed/picoclaw/pkg/providers"
 	"github.com/sipeed/picoclaw/pkg/skills"
@@ -22,11 +23,7 @@ type ContextBuilder struct {
 }
 
 func getGlobalConfigDir() string {
-	home, err := os.UserHomeDir()
-	if err != nil {
-		return ""
-	}
-	return filepath.Join(home, ".picoclaw")
+	return config.ResolveRuntimePaths().HomeDir
 }
 
 func NewContextBuilder(workspace string) *ContextBuilder {
diff --git a/pkg/agent/context_test.go b/pkg/agent/context_test.go
new file mode 100644
index 000000000..00eb5235e
--- /dev/null
+++ b/pkg/agent/context_test.go
@@ -0,0 +1,31 @@
+package agent
+
+import (
+	"path/filepath"
+	"testing"
+
+	"github.com/sipeed/picoclaw/pkg/config"
+)
+
+func TestGetGlobalConfigDir_UsesPicoClawHomeOverride(t *testing.T) {
+	homeOverride := filepath.Join(t.TempDir(), "pico-home")
+	t.Setenv(config.EnvPicoClawConfig, "")
+	t.Setenv(config.EnvPicoClawHome, homeOverride)
+
+	if got := getGlobalConfigDir(); got != homeOverride {
+		t.Errorf("getGlobalConfigDir() = %q, want %q", got, homeOverride)
+	}
+}
+
+func TestGetGlobalConfigDir_ConfigOverrideTakesPrecedence(t *testing.T) {
+	homeOverride := filepath.Join(t.TempDir(), "pico-home")
+	configDir := filepath.Join(t.TempDir(), "custom-config-dir")
+	configPath := filepath.Join(configDir, "config.json")
+
+	t.Setenv(config.EnvPicoClawHome, homeOverride)
+	t.Setenv(config.EnvPicoClawConfig, configPath)
+
+	if got := getGlobalConfigDir(); got != configDir {
+		t.Errorf("getGlobalConfigDir() = %q, want %q", got, configDir)
+	}
+}
diff --git a/pkg/auth/store.go b/pkg/auth/store.go
index 20724929a..0bf622a2e 100644
--- a/pkg/auth/store.go
+++ b/pkg/auth/store.go
@@ -5,6 +5,8 @@ import (
 	"os"
 	"path/filepath"
 	"time"
+
+	"github.com/sipeed/picoclaw/pkg/config"
 )
 
 type AuthCredential struct {
@@ -35,8 +37,7 @@ func (c *AuthCredential) NeedsRefresh() bool {
 }
 
 func authFilePath() string {
-	home, _ := os.UserHomeDir()
-	return filepath.Join(home, ".picoclaw", "auth.json")
+	return config.ResolveRuntimePaths().AuthPath
 }
 
 func LoadStore() (*AuthStore, error) {
diff --git a/pkg/auth/store_test.go b/pkg/auth/store_test.go
index d96b460a1..57228f497 100644
--- a/pkg/auth/store_test.go
+++ b/pkg/auth/store_test.go
@@ -5,6 +5,8 @@ import (
 	"path/filepath"
 	"testing"
 	"time"
+
+	"github.com/sipeed/picoclaw/pkg/config"
 )
 
 func TestAuthCredentialIsExpired(t *testing.T) {
@@ -102,7 +104,7 @@ func TestStoreFilePermissions(t *testing.T) {
 		t.Fatalf("SetCredential() error: %v", err)
 	}
 
-	path := filepath.Join(tmpDir, ".picoclaw", "auth.json")
+	path := config.ResolveRuntimePaths().AuthPath
 	info, err := os.Stat(path)
 	if err != nil {
 		t.Fatalf("Stat() error: %v", err)
@@ -187,3 +189,53 @@ func TestLoadStoreEmpty(t *testing.T) {
 		t.Errorf("expected empty credentials, got %d", len(store.Credentials))
 	}
 }
+
+func TestStoreUsesPicoClawHomeOverride(t *testing.T) {
+	baseDir := t.TempDir()
+	home := filepath.Join(baseDir, "home")
+	override := filepath.Join(baseDir, "pico-home")
+
+	t.Setenv("HOME", home)
+	t.Setenv(config.EnvPicoClawConfig, "")
+	t.Setenv(config.EnvPicoClawHome, override)
+
+	cred := &AuthCredential{
+		AccessToken: "override-token",
+		Provider:    "openai",
+		AuthMethod:  "oauth",
+	}
+	if err := SetCredential("openai", cred); err != nil {
+		t.Fatalf("SetCredential() error: %v", err)
+	}
+
+	expectedPath := filepath.Join(override, "auth.json")
+	if _, err := os.Stat(expectedPath); err != nil {
+		t.Fatalf("expected auth store at %s, got stat error: %v", expectedPath, err)
+	}
+}
+
+func TestStoreUsesConfigDirectoryWhenConfigOverrideSet(t *testing.T) {
+	baseDir := t.TempDir()
+	home := filepath.Join(baseDir, "home")
+	homeOverride := filepath.Join(baseDir, "pico-home")
+	configDir := filepath.Join(baseDir, "custom-config-dir")
+	configPath := filepath.Join(configDir, "config.json")
+
+	t.Setenv("HOME", home)
+	t.Setenv(config.EnvPicoClawHome, homeOverride)
+	t.Setenv(config.EnvPicoClawConfig, configPath)
+
+	cred := &AuthCredential{
+		AccessToken: "config-override-token",
+		Provider:    "openai",
+		AuthMethod:  "oauth",
+	}
+	if err := SetCredential("openai", cred); err != nil {
+		t.Fatalf("SetCredential() error: %v", err)
+	}
+
+	expectedPath := filepath.Join(configDir, "auth.json")
+	if _, err := os.Stat(expectedPath); err != nil {
+		t.Fatalf("expected auth store at %s, got stat error: %v", expectedPath, err)
+	}
+}
diff --git a/pkg/config/config.go b/pkg/config/config.go
index d189ff00b..edb3893be 100644
--- a/pkg/config/config.go
+++ b/pkg/config/config.go
@@ -339,14 +339,13 @@ func LoadConfig(path string) (*Config, error) {
 
 	data, err := os.ReadFile(path)
 	if err != nil {
-		if os.IsNotExist(err) {
-			return cfg, nil
+		if !os.IsNotExist(err) {
+			return nil, err
+		}
+	} else {
+		if err := json.Unmarshal(data, cfg); err != nil {
+			return nil, err
 		}
-		return nil, err
-	}
-
-	if err := json.Unmarshal(data, cfg); err != nil {
-		return nil, err
 	}
 
 	if err := env.Parse(cfg); err != nil {
diff --git a/pkg/config/config_test.go b/pkg/config/config_test.go
index febfd0456..d2c23d696 100644
--- a/pkg/config/config_test.go
+++ b/pkg/config/config_test.go
@@ -204,3 +204,17 @@ func TestConfig_Complete(t *testing.T) {
 		t.Error("Heartbeat should be enabled by default")
 	}
 }
+
+func TestLoadConfig_AppliesEnvWithoutConfigFile(t *testing.T) {
+	t.Setenv("PICOCLAW_AGENTS_DEFAULTS_MODEL", "env-only-model")
+
+	missingPath := filepath.Join(t.TempDir(), "missing-config.json")
+	cfg, err := LoadConfig(missingPath)
+	if err != nil {
+		t.Fatalf("LoadConfig() error: %v", err)
+	}
+
+	if cfg.Agents.Defaults.Model != "env-only-model" {
+		t.Errorf("Model = %q, want %q", cfg.Agents.Defaults.Model, "env-only-model")
+	}
+}
diff --git a/pkg/config/paths.go b/pkg/config/paths.go
new file mode 100644
index 000000000..a67a17360
--- /dev/null
+++ b/pkg/config/paths.go
@@ -0,0 +1,49 @@
+package config
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+const (
+	EnvPicoClawConfig = "PICOCLAW_CONFIG"
+	EnvPicoClawHome   = "PICOCLAW_HOME"
+)
+
+type RuntimePaths struct {
+	HomeDir         string
+	ConfigPath      string
+	AuthPath        string
+	GlobalSkillsDir string
+}
+
+func ResolveRuntimePaths() RuntimePaths {
+	if configPath := expandHome(strings.TrimSpace(os.Getenv(EnvPicoClawConfig))); configPath != "" {
+		return buildRuntimePaths(filepath.Dir(configPath), configPath)
+	}
+
+	homeDir := expandHome(strings.TrimSpace(os.Getenv(EnvPicoClawHome)))
+	if homeDir == "" {
+		homeDir = defaultPicoClawHome()
+	}
+
+	return buildRuntimePaths(homeDir, filepath.Join(homeDir, "config.json"))
+}
+
+func defaultPicoClawHome() string {
+	home, err := os.UserHomeDir()
+	if err != nil || home == "" {
+		return ".picoclaw"
+	}
+	return filepath.Join(home, ".picoclaw")
+}
+
+func buildRuntimePaths(homeDir, configPath string) RuntimePaths {
+	return RuntimePaths{
+		HomeDir:         homeDir,
+		ConfigPath:      configPath,
+		AuthPath:        filepath.Join(homeDir, "auth.json"),
+		GlobalSkillsDir: filepath.Join(homeDir, "skills"),
+	}
+}
diff --git a/pkg/config/paths_test.go b/pkg/config/paths_test.go
new file mode 100644
index 000000000..d307a66f9
--- /dev/null
+++ b/pkg/config/paths_test.go
@@ -0,0 +1,74 @@
+package config
+
+import (
+	"path/filepath"
+	"testing"
+)
+
+func TestResolveRuntimePaths_Default(t *testing.T) {
+	home := t.TempDir()
+	t.Setenv("HOME", home)
+	t.Setenv(EnvPicoClawConfig, "")
+	t.Setenv(EnvPicoClawHome, "")
+
+	paths := ResolveRuntimePaths()
+	wantHome := filepath.Join(home, ".picoclaw")
+
+	if paths.HomeDir != wantHome {
+		t.Errorf("HomeDir = %q, want %q", paths.HomeDir, wantHome)
+	}
+	if paths.ConfigPath != filepath.Join(wantHome, "config.json") {
+		t.Errorf("ConfigPath = %q, want %q", paths.ConfigPath, filepath.Join(wantHome, "config.json"))
+	}
+	if paths.AuthPath != filepath.Join(wantHome, "auth.json") {
+		t.Errorf("AuthPath = %q, want %q", paths.AuthPath, filepath.Join(wantHome, "auth.json"))
+	}
+	if paths.GlobalSkillsDir != filepath.Join(wantHome, "skills") {
+		t.Errorf("GlobalSkillsDir = %q, want %q", paths.GlobalSkillsDir, filepath.Join(wantHome, "skills"))
+	}
+}
+
+func TestResolveRuntimePaths_UsesPicoClawHomeOverride(t *testing.T) {
+	homeOverride := filepath.Join(t.TempDir(), "pico-home")
+	t.Setenv(EnvPicoClawConfig, "")
+	t.Setenv(EnvPicoClawHome, homeOverride)
+
+	paths := ResolveRuntimePaths()
+
+	if paths.HomeDir != homeOverride {
+		t.Errorf("HomeDir = %q, want %q", paths.HomeDir, homeOverride)
+	}
+	if paths.ConfigPath != filepath.Join(homeOverride, "config.json") {
+		t.Errorf("ConfigPath = %q, want %q", paths.ConfigPath, filepath.Join(homeOverride, "config.json"))
+	}
+	if paths.AuthPath != filepath.Join(homeOverride, "auth.json") {
+		t.Errorf("AuthPath = %q, want %q", paths.AuthPath, filepath.Join(homeOverride, "auth.json"))
+	}
+	if paths.GlobalSkillsDir != filepath.Join(homeOverride, "skills") {
+		t.Errorf("GlobalSkillsDir = %q, want %q", paths.GlobalSkillsDir, filepath.Join(homeOverride, "skills"))
+	}
+}
+
+func TestResolveRuntimePaths_ConfigOverrideTakesPrecedence(t *testing.T) {
+	homeOverride := filepath.Join(t.TempDir(), "pico-home")
+	configDir := filepath.Join(t.TempDir(), "custom-config-dir")
+	configPath := filepath.Join(configDir, "config.json")
+
+	t.Setenv(EnvPicoClawHome, homeOverride)
+	t.Setenv(EnvPicoClawConfig, configPath)
+
+	paths := ResolveRuntimePaths()
+
+	if paths.ConfigPath != configPath {
+		t.Errorf("ConfigPath = %q, want %q", paths.ConfigPath, configPath)
+	}
+	if paths.HomeDir != configDir {
+		t.Errorf("HomeDir = %q, want %q", paths.HomeDir, configDir)
+	}
+	if paths.AuthPath != filepath.Join(configDir, "auth.json") {
+		t.Errorf("AuthPath = %q, want %q", paths.AuthPath, filepath.Join(configDir, "auth.json"))
+	}
+	if paths.GlobalSkillsDir != filepath.Join(configDir, "skills") {
+		t.Errorf("GlobalSkillsDir = %q, want %q", paths.GlobalSkillsDir, filepath.Join(configDir, "skills"))
+	}
+}