diff --git a/internal/auth/auth_test.go b/internal/auth/auth_test.go
index 422875b8..544d6cf5 100644
--- a/internal/auth/auth_test.go
+++ b/internal/auth/auth_test.go
@@ -29,6 +29,7 @@ func TestPasswordCrypto(t *testing.T) {
 
 func TestAuthStoreMemory_Operations(t *testing.T) {
 	cfg := &config.Config{
+		Env:                     "dev",
 		AdminUsername:           "superadmin",
 		AdminPassword:           "admin-test-pass-999",
 		AuthRegistrationEnabled: true,
diff --git a/internal/auth/store.go b/internal/auth/store.go
index 781bcf3b..1ae25e08 100644
--- a/internal/auth/store.go
+++ b/internal/auth/store.go
@@ -76,40 +76,46 @@ func NewMemoryStore(cfg *config.Config) *MemoryStore {
 	}
 	store.nextID = 2
 
-	// 2. 初始化标准测试用户 (统一初始密码: 123456)
-	defaultPassHash, _ := HashPassword("123456")
-	seedUsers := []struct {
-		id         int64
-		username   string
-		name       string
-		roleID     string
-		position   string
-		dept       string
-		employeeID string
-	}{
-		{2, "zhanggong", "张工", "role-engineer", "方案工程师", "骨科耗材研发组", "RD-001"},
-		{3, "lizhuguan", "李主管", "role-tech-lead", "技术主管", "骨科耗材研发组", "RD-002"},
-		{4, "wangzong", "王总监", "role-director", "研发总监", "研发中心", "RD-003"},
-		{5, "guest", "访客", "role-guest", "待指派", "外协中心", "EXT-999"},
+	// 2. 标准测试用户仅 dev/test 环境种子化；生产不得携带固定密码演示账号
+	env := ""
+	if cfg != nil {
+		env = cfg.Env
 	}
-
-	for _, su := range seedUsers {
-		store.users[su.id] = &UserAccount{
-			ID:                 su.id,
-			Username:           su.username,
-			Name:               su.name,
-			PasswordHash:       defaultPassHash,
-			Status:             StatusActive,
-			MustChangePassword: false,
-			RoleID:             su.roleID,
-			Position:           su.position,
-			Department:         su.dept,
-			EmployeeID:         su.employeeID,
-			CreatedAt:          now,
-			UpdatedAt:          now,
+	if env == "dev" || env == "test" || env == "" {
+		defaultPassHash, _ := HashPassword("123456")
+		seedUsers := []struct {
+			id         int64
+			username   string
+			name       string
+			roleID     string
+			position   string
+			dept       string
+			employeeID string
+		}{
+			{2, "zhanggong", "张工", "role-engineer", "方案工程师", "骨科耗材研发组", "RD-001"},
+			{3, "lizhuguan", "李主管", "role-tech-lead", "技术主管", "骨科耗材研发组", "RD-002"},
+			{4, "wangzong", "王总监", "role-director", "研发总监", "研发中心", "RD-003"},
+			{5, "guest", "访客", "role-guest", "待指派", "外协中心", "EXT-999"},
 		}
-		if su.id >= store.nextID {
-			store.nextID = su.id + 1
+
+		for _, su := range seedUsers {
+			store.users[su.id] = &UserAccount{
+				ID:                 su.id,
+				Username:           su.username,
+				Name:               su.name,
+				PasswordHash:       defaultPassHash,
+				Status:             StatusActive,
+				MustChangePassword: false,
+				RoleID:             su.roleID,
+				Position:           su.position,
+				Department:         su.dept,
+				EmployeeID:         su.employeeID,
+				CreatedAt:          now,
+				UpdatedAt:          now,
+			}
+			if su.id >= store.nextID {
+				store.nextID = su.id + 1
+			}
 		}
 	}
 
diff --git a/internal/auth/store_test.go b/internal/auth/store_test.go
new file mode 100644
index 00000000..19342b4b
--- /dev/null
+++ b/internal/auth/store_test.go
@@ -0,0 +1,49 @@
+package auth_test
+
+import (
+	"context"
+	"testing"
+
+	"chat-agent-system/internal/auth"
+	"chat-agent-system/internal/config"
+)
+
+func TestMemoryStore_DevEnvSeedsDemoUsers(t *testing.T) {
+	cfg := &config.Config{Env: "dev", AdminPassword: "admin-test-pass-999"}
+	store := auth.NewMemoryStore(cfg)
+	ctx := context.Background()
+
+	user, err := store.GetUserByUsername(ctx, "zhanggong")
+	if err != nil {
+		t.Fatalf("expected zhanggong in dev env: %v", err)
+	}
+	if user.RoleID != "role-engineer" {
+		t.Fatalf("unexpected role: %s", user.RoleID)
+	}
+}
+
+func TestMemoryStore_MainEnvNoSeedUsers(t *testing.T) {
+	cfg := &config.Config{
+		Env:           "main",
+		AdminPassword: "secure-main-admin-pass-xyz",
+	}
+	store := auth.NewMemoryStore(cfg)
+	ctx := context.Background()
+
+	if _, err := store.GetUserByUsername(ctx, "zhanggong"); err == nil {
+		t.Fatal("main env must not seed zhanggong demo user")
+	}
+	if _, err := store.GetUserByUsername(ctx, "guest"); err == nil {
+		t.Fatal("main env must not seed guest demo user")
+	}
+	admin, err := store.GetUserByUsername(ctx, cfg.AdminUsername)
+	if err != nil && cfg.AdminUsername == "" {
+		admin, err = store.GetUserByUsername(ctx, "admin")
+	}
+	if err != nil {
+		t.Fatalf("admin account should still exist: %v", err)
+	}
+	if admin.RoleID != "role-admin" {
+		t.Fatalf("expected role-admin, got %s", admin.RoleID)
+	}
+}
diff --git a/internal/server/auth_middleware.go b/internal/server/auth_middleware.go
index 30e4eb4c..f2f3abbf 100644
--- a/internal/server/auth_middleware.go
+++ b/internal/server/auth_middleware.go
@@ -6,7 +6,14 @@ import (
 )
 
 func (s *Server) allowLegacyTestPrincipal() bool {
-	return s.cfg != nil && s.cfg.AllowInMemory && s.cfg.ContextDbHost == ""
+	if s.cfg == nil {
+		return false
+	}
+	env := s.cfg.Env
+	if env != "dev" && env != "test" && env != "" {
+		return false
+	}
+	return s.cfg.AllowInMemory && s.cfg.ContextDbHost == ""
 }
 
 func isPublicRoute(method, path string) bool {
diff --git a/internal/server/test_auth_helpers.go b/internal/server/test_auth_helpers.go
index 474883cf..5d8867e5 100644
--- a/internal/server/test_auth_helpers.go
+++ b/internal/server/test_auth_helpers.go
@@ -5,7 +5,6 @@ import (
 	"encoding/json"
 	"net/http"
 	"net/http/httptest"
-	"strconv"
 	"testing"
 
 	"chat-agent-system/internal/auth"
@@ -47,7 +46,7 @@ func withBearerAuth(req *http.Request, token string) {
 	req.Header.Set("Authorization", "Bearer "+token)
 }
 
-// withUserIDAuth 为请求附加 X-User-ID（用户必须已存在于 auth store）。
-func withUserIDAuth(req *http.Request, userID int64) {
-	req.Header.Set("X-User-ID", strconv.FormatInt(userID, 10))
+// withBearerToken 为请求附加 Authorization Bearer Token（Phase 0：不再使用 X-User-ID）。
+func withBearerToken(req *http.Request, token string) {
+	req.Header.Set("Authorization", "Bearer "+token)
 }