diff --git a/internal/route/route.go b/internal/route/route.go
index 94c7d5c..2b0957a 100644
--- a/internal/route/route.go
+++ b/internal/route/route.go
@@ -48,6 +48,29 @@ import (
 	"github.com/tamakyi/TamaBox/templates"
 )
 
+func sessionOptions() session.Options {
+	options := session.Options{
+		Initer: session.MemoryIniter(),
+		Cookie: session.CookieOptions{
+			HTTPOnly: true,
+			SameSite: http.SameSiteLaxMode,
+			Secure:   strings.HasPrefix(conf.App.ExternalURL, "https"),
+		},
+	}
+	if conf.Database.DSN != "" && (conf.Database.Type == "" || conf.Database.Type == "mysql") {
+		options.Initer = mysql.Initer()
+		options.Config = mysql.Config{DSN: conf.Database.DSN, Lifetime: 7 * 24 * time.Hour}
+	}
+	if conf.Redis.Addr != "" {
+		options.Initer = sessionRedis.Initer()
+		options.Config = sessionRedis.Config{
+			Options:  &sessionRedis.Options{Addr: conf.Redis.Addr, Password: conf.Redis.Password, DB: 1},
+			Lifetime: 7 * 24 * time.Hour,
+		}
+	}
+	return options
+}
+
 // indexNowKeyPattern 限制 IndexNow 密钥文件名的合法形态：32 位小写十六进制 + ".txt"。
 // 用于防止把路由参数直接拼进 embed FS 路径时发生路径穿越（如 "../robots.txt"）。
 var indexNowKeyPattern = regexp.MustCompile(`^[0-9a-f]{32}\.txt$`)
@@ -243,38 +266,7 @@ func New() *flamego.Flame {
 	gob.Register(time.Time{})
 	gob.Register(context.Flash{})
 	gob.Register(captcha.StoredAnswer{})
-	var sessionStorage interface{}
-	initer := session.MemoryIniter()
-	if conf.Database.DSN != "" {
-		initer = mysql.Initer()
-		sessionStorage = mysql.Config{
-			DSN:      conf.Database.DSN,
-			Lifetime: 7 * 24 * time.Hour,
-		}
-	}
-	if conf.Redis.Addr != "" {
-		initer = sessionRedis.Initer()
-		sessionStorage = sessionRedis.Config{
-			Options: &sessionRedis.Options{
-				Addr:     conf.Redis.Addr,
-				Password: conf.Redis.Password,
-				DB:       1,
-			},
-			Lifetime: 7 * 24 * time.Hour,
-		}
-	}
-	sessioner := session.Sessioner(session.Options{
-		Initer: initer,
-		Config: sessionStorage,
-		// 显式声明 cookie 安全属性：HTTPOnly 防 XSS 窃取会话；SameSite=Lax 阻断跨站表单
-		// POST；Secure 仅在 https 对外服务时下发，避免 http 本地开发下 cookie 不生效
-		// （缺失 Secure 时，HSTS 尚未落地的首次访问可被 MITM 诱导明文请求窃取会话）。
-		Cookie: session.CookieOptions{
-			HTTPOnly: true,
-			SameSite: http.SameSiteLaxMode,
-			Secure:   strings.HasPrefix(conf.App.ExternalURL, "https"),
-		},
-	})
+	sessioner := session.Sessioner(sessionOptions())
 
 	// 安全响应头必须注册在静态资源之前：flamego.Static 命中后会终结请求链，
 	// 放在它后面等于静态资源拿不到 nosniff / HSTS。
diff --git a/internal/route/session_options_test.go b/internal/route/session_options_test.go
new file mode 100644
index 0000000..6258bdd
--- /dev/null
+++ b/internal/route/session_options_test.go
@@ -0,0 +1,52 @@
+package route
+
+import (
+	"testing"
+
+	"github.com/flamego/session/mysql"
+	sessionRedis "github.com/flamego/session/redis"
+	"github.com/stretchr/testify/require"
+
+	"github.com/tamakyi/TamaBox/internal/conf"
+)
+
+func TestSessionOptionsSelectStorageByDatabaseAndRedis(t *testing.T) {
+	oldDatabase, oldRedis, oldExternalURL := conf.Database, conf.Redis, conf.App.ExternalURL
+	t.Cleanup(func() {
+		conf.Database, conf.Redis, conf.App.ExternalURL = oldDatabase, oldRedis, oldExternalURL
+	})
+	conf.Database.DSN = "test-database-dsn"
+	conf.App.ExternalURL = "https://example.test"
+
+	for _, tt := range []struct {
+		name         string
+		databaseType string
+		redisAddr    string
+		configType   interface{}
+	}{
+		{name: "postgres without redis uses memory", databaseType: "postgres"},
+		{name: "postgres with redis uses redis", databaseType: "postgres", redisAddr: "127.0.0.1:6379", configType: sessionRedis.Config{}},
+		{name: "mysql without redis uses mysql", databaseType: "mysql", configType: mysql.Config{}},
+		{name: "mysql with redis uses redis", databaseType: "mysql", redisAddr: "127.0.0.1:6379", configType: sessionRedis.Config{}},
+		{name: "legacy empty database type uses mysql", configType: mysql.Config{}},
+	} {
+		t.Run(tt.name, func(t *testing.T) {
+			conf.Database.Type = tt.databaseType
+			conf.Redis.Addr = tt.redisAddr
+			conf.Redis.Password = "test-only-password"
+			opts := sessionOptions()
+			if tt.configType == nil {
+				require.Nil(t, opts.Config)
+				return
+			}
+			require.IsType(t, tt.configType, opts.Config)
+			switch cfg := opts.Config.(type) {
+			case mysql.Config:
+				require.Equal(t, conf.Database.DSN, cfg.DSN)
+			case sessionRedis.Config:
+				require.Equal(t, tt.redisAddr, cfg.Options.Addr)
+				require.Equal(t, 1, cfg.Options.DB)
+			}
+		})
+	}
+}