diff --git a/app/src/main/java/cn/flyzxf/FengTv/MainActivity.kt b/app/src/main/java/cn/flyzxf/FengTv/MainActivity.kt
index 483a6bb..d2f0fcb 100644
--- a/app/src/main/java/cn/flyzxf/FengTv/MainActivity.kt
+++ b/app/src/main/java/cn/flyzxf/FengTv/MainActivity.kt
@@ -60,9 +60,11 @@ class MainActivity : AppCompatActivity() {
     private var retryCount = 0
     private val maxRetries = 3
     private var isFirstLaunch = true
-    private var hasShownNetworkRetryToast = false
     private var isReverseOrder = false
     private var isToolbarShowing = false
+    // 下载源重试状态
+    private var downloadRetryCount = 0
+    private val maxDownloadRetries = 6
 
     // 频道名消失 Runnable
     private val hideChannelNameRunnable = Runnable {
@@ -81,10 +83,8 @@ class MainActivity : AppCompatActivity() {
         private const val KEY_REVERSE = "reverse_order"
         private const val TIMEOUT_MS = 3000
         private const val CHANNEL_NAME_DURATION_MS = 3000L
-        private const val NETWORK_DELAY_MS = 5000L
         private const val TOOLBAR_DURATION_MS = 5000L
         private const val LOADING_TIMEOUT_MS = 4000L
-        private const val SWITCH_STATUS_DURATION_MS = 2000L
     }
 
     override fun onCreate(savedInstanceState: Bundle?) {
@@ -345,7 +345,7 @@ class MainActivity : AppCompatActivity() {
             return
         }
 
-        hasShownNetworkRetryToast = false
+        downloadRetryCount = 0
 
         val channels = ChannelManager.loadChannels(this)
         if (channels.isNotEmpty()) {
@@ -358,12 +358,28 @@ class MainActivity : AppCompatActivity() {
 
         val sourceUrl = ChannelManager.getSavedSourceUrl(this)
         if (sourceUrl != null) {
-            executor.execute {
-                downloadAndUpdateSource(sourceUrl)
+            // 先检查网络是否可用，如果没网就不立即尝试下载
+            if (isNetworkAvailable()) {
+                executor.execute {
+                    downloadAndUpdateSource(sourceUrl)
+                }
+            } else {
+                // 没网 → 等网络回调
+                if (channels.isEmpty()) {
+                    loadingText.text = "等待网络连接后自动下载频道列表..."
+                }
+                // registerNetworkCallback 会在网络连上时自动触发下载
             }
         }
     }
 
+    private fun isNetworkAvailable(): Boolean {
+        val cm = getSystemService(CONNECTIVITY_SERVICE) as ConnectivityManager
+        val network = cm.activeNetwork ?: return false
+        val caps = cm.getNetworkCapabilities(network) ?: return false
+        return caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET)
+    }
+
     private fun downloadAndUpdateSource(sourceUrl: String) {
         try {
             val url = URL(sourceUrl)
@@ -382,6 +398,7 @@ class MainActivity : AppCompatActivity() {
                     val channelCountBefore = ChannelManager.getChannelCount()
                     ChannelManager.saveChannels(this, lines)
                     val newCount = ChannelManager.getChannelCount()
+                    downloadRetryCount = 0  // 成功，重置重试
                     mainHandler.post {
                         if (channelCountBefore == 0 && newCount > 0) {
                             playChannel(ChannelManager.getCurrentChannel()!!)
@@ -398,21 +415,30 @@ class MainActivity : AppCompatActivity() {
             conn.disconnect()
         } catch (e: Exception) {
             e.printStackTrace()
-            if (ChannelManager.getChannelCount() == 0) {
-                if (!hasShownNetworkRetryToast) {
-                    hasShownNetworkRetryToast = true
-                    mainHandler.post {
-                        Toast.makeText(this@MainActivity, "无法连接服务器，将在后台继续尝试...", Toast.LENGTH_LONG).show()
+            downloadRetryCount++
+            if (downloadRetryCount >= maxDownloadRetries) {
+                // 达到最大重试次数，停止
+                mainHandler.post {
+                    if (ChannelManager.getChannelCount() == 0) {
+                        loadingText.text = "多次尝试失败，请检查网络或源地址"
+                        Toast.makeText(this@MainActivity, "多次尝试下载失败", Toast.LENGTH_LONG).show()
+                    } else {
+                        Toast.makeText(this@MainActivity, "更新失败，使用缓存", Toast.LENGTH_SHORT).show()
                     }
                 }
-                mainHandler.postDelayed({
-                    executor.execute { downloadAndUpdateSource(sourceUrl) }
-                }, NETWORK_DELAY_MS)
-            } else {
-                mainHandler.post {
-                    Toast.makeText(this@MainActivity, "更新源失败，使用缓存", Toast.LENGTH_SHORT).show()
+                return
+            }
+            // 指数退避：5s → 10s → 20s → 40s → 60s → 120s
+            val delays = longArrayOf(5000, 10000, 20000, 40000, 60000, 120000)
+            val delay = delays.getOrElse(downloadRetryCount - 1) { 120000L }
+            mainHandler.post {
+                if (ChannelManager.getChannelCount() == 0) {
+                    loadingText.text = "连接失败，${delay / 1000}秒后重试(${downloadRetryCount}/$maxDownloadRetries)"
                 }
             }
+            mainHandler.postDelayed({
+                executor.execute { downloadAndUpdateSource(sourceUrl) }
+            }, delay)
         }
     }
 
@@ -562,7 +588,9 @@ class MainActivity : AppCompatActivity() {
         connectivityManager.registerNetworkCallback(builder.build(), object : ConnectivityManager.NetworkCallback() {
             override fun onAvailable(network: Network) {
                 val sourceUrl = ChannelManager.getSavedSourceUrl(this@MainActivity)
-                if (sourceUrl != null && ChannelManager.getChannelCount() > 0) {
+                if (sourceUrl != null) {
+                    // 网络恢复，重置重试计数并尝试下载
+                    downloadRetryCount = 0
                     executor.execute {
                         downloadAndUpdateSource(sourceUrl)
                     }