diff --git a/flomo-ai/app/src/main/java/com/example/flomo_ai/SecondActivity.kt b/flomo-ai/app/src/main/java/com/example/flomo_ai/SecondActivity.kt
index 2816a5f..14660c9 100644
--- a/flomo-ai/app/src/main/java/com/example/flomo_ai/SecondActivity.kt
+++ b/flomo-ai/app/src/main/java/com/example/flomo_ai/SecondActivity.kt
@@ -12,6 +12,8 @@ import android.widget.CheckBox
 import android.widget.EditText
 import android.widget.ImageButton
 import android.widget.LinearLayout
+import android.widget.RadioButton
+import android.widget.RadioGroup
 import android.widget.Spinner
 import android.widget.TextView
 import android.widget.Toast
@@ -60,6 +62,10 @@ class SecondActivity : AppCompatActivity() {
 
     private lateinit var promptContainer: LinearLayout
     private lateinit var btnAddPrompt: Button
+    private lateinit var rgTheme: RadioGroup
+    private lateinit var rbThemeLight: RadioButton
+    private lateinit var rbThemeDark: RadioButton
+    private lateinit var rbThemeAuto: RadioButton
 
     private var llmConfigs = mutableListOf<LLMConfig>()
     private var promptConfigs = mutableListOf<PromptConfig>()
@@ -109,6 +115,29 @@ class SecondActivity : AppCompatActivity() {
 
         promptContainer = findViewById(R.id.promptContainer)
         btnAddPrompt = findViewById(R.id.btnAddPrompt)
+        rgTheme = findViewById(R.id.rgTheme)
+        rbThemeLight = findViewById(R.id.rbThemeLight)
+        rbThemeDark = findViewById(R.id.rbThemeDark)
+        rbThemeAuto = findViewById(R.id.rbThemeAuto)
+
+        // 设置当前主题
+        when (ThemeManager.getThemeMode(this)) {
+            ThemeManager.THEME_LIGHT -> rbThemeLight.isChecked = true
+            ThemeManager.THEME_DARK -> rbThemeDark.isChecked = true
+            else -> rbThemeAuto.isChecked = true
+        }
+
+        // 主题切换监听
+        rgTheme.setOnCheckedChangeListener { _, checkedId ->
+            val mode = when (checkedId) {
+                R.id.rbThemeLight -> ThemeManager.THEME_LIGHT
+                R.id.rbThemeDark -> ThemeManager.THEME_DARK
+                else -> ThemeManager.THEME_FOLLOW_SYSTEM
+            }
+            ThemeManager.setThemeMode(this, mode)
+        }
+
+        btnAddPrompt.setOnClickListener { showAddPromptDialog() }
 
         btnToggleApiKey1.setOnClickListener { toggleApiKeyVisibility(etApiKey1, btnToggleApiKey1) }
         btnToggleApiKey2.setOnClickListener { toggleApiKeyVisibility(etApiKey2, btnToggleApiKey2) }
@@ -117,8 +146,6 @@ class SecondActivity : AppCompatActivity() {
         btnTestConnection1.setOnClickListener { testConnection1() }
         btnTestConnection2.setOnClickListener { testConnection2() }
         btnTestConnection3.setOnClickListener { testConnection3() }
-
-        btnAddPrompt.setOnClickListener { showAddPromptDialog() }
     }
 
     private fun loadConfigurations() {
diff --git a/flomo-ai/app/src/main/res/layout/activity_second.xml b/flomo-ai/app/src/main/res/layout/activity_second.xml
index 02ee005..c8ab113 100644
--- a/flomo-ai/app/src/main/res/layout/activity_second.xml
+++ b/flomo-ai/app/src/main/res/layout/activity_second.xml
@@ -486,6 +486,52 @@
                 </LinearLayout>
             </LinearLayout>
 
+            <!-- 主题设置 -->
+            <TextView
+                android:layout_width="wrap_content"
+                android:layout_height="wrap_content"
+                android:text="主题"
+                android:textSize="15sp"
+                android:textStyle="bold"
+                android:textColor="@color/text_primary"
+                android:layout_marginTop="16dp"
+                android:layout_marginBottom="12dp"/>
+
+            <RadioGroup
+                android:id="@+id/rgTheme"
+                android:layout_width="match_parent"
+                android:layout_height="wrap_content"
+                android:orientation="vertical">
+
+                <RadioButton
+                    android:id="@+id/rbThemeLight"
+                    android:layout_width="match_parent"
+                    android:layout_height="44dp"
+                    android:text="☀️ 白天"
+                    android:textSize="14sp"
+                    android:textColor="@color/text_primary"
+                    android:paddingStart="8dp"/>
+
+                <RadioButton
+                    android:id="@+id/rbThemeDark"
+                    android:layout_width="match_parent"
+                    android:layout_height="44dp"
+                    android:text="🌙 黑夜"
+                    android:textSize="14sp"
+                    android:textColor="@color/text_primary"
+                    android:paddingStart="8dp"/>
+
+                <RadioButton
+                    android:id="@+id/rbThemeAuto"
+                    android:layout_width="match_parent"
+                    android:layout_height="44dp"
+                    android:text="⚙️ 自动跟随系统"
+                    android:textSize="14sp"
+                    android:textColor="@color/text_primary"
+                    android:paddingStart="8dp"/>
+
+            </RadioGroup>
+
             <!-- 提示词管理 -->
             <TextView
                 android:layout_width="wrap_content"