diff --git a/backend/internal/config/config.go b/backend/internal/config/config.go
index c1e15290..aaaaf3bd 100644
--- a/backend/internal/config/config.go
+++ b/backend/internal/config/config.go
@@ -544,7 +544,7 @@ func setDefaults() {
 	viper.SetDefault("gateway.concurrency_slot_ttl_minutes", 30) // 并发槽位过期时间（支持超长请求）
 	viper.SetDefault("gateway.stream_data_interval_timeout", 180)
 	viper.SetDefault("gateway.stream_keepalive_interval", 10)
-	viper.SetDefault("gateway.max_line_size", 10*1024*1024)
+	viper.SetDefault("gateway.max_line_size", 25*1024*1024)
 	viper.SetDefault("gateway.scheduling.sticky_session_max_waiting", 3)
 	viper.SetDefault("gateway.scheduling.sticky_session_wait_timeout", 45*time.Second)
 	viper.SetDefault("gateway.scheduling.fallback_wait_timeout", 30*time.Second)
diff --git a/backend/internal/service/gateway_service.go b/backend/internal/service/gateway_service.go
index 209e4dee..63245933 100644
--- a/backend/internal/service/gateway_service.go
+++ b/backend/internal/service/gateway_service.go
@@ -33,7 +33,7 @@ const (
 	claudeAPIURL            = "https://api.anthropic.com/v1/messages?beta=true"
 	claudeAPICountTokensURL = "https://api.anthropic.com/v1/messages/count_tokens?beta=true"
 	stickySessionTTL        = time.Hour // 粘性会话TTL
-	defaultMaxLineSize      = 10 * 1024 * 1024
+	defaultMaxLineSize      = 25 * 1024 * 1024
 	claudeCodeSystemPrompt  = "You are Claude Code, Anthropic's official CLI for Claude."
 	maxCacheControlBlocks   = 4 // Anthropic API 允许的最大 cache_control 块数量
 )
diff --git a/config.yaml b/config.yaml
index f43c9c19..c282bf9a 100644
--- a/config.yaml
+++ b/config.yaml
@@ -154,9 +154,9 @@ gateway:
   # Stream keepalive interval (seconds), 0=disable
   # 流式 keepalive 间隔（秒），0=禁用
   stream_keepalive_interval: 10
-  # SSE max line size in bytes (default: 10MB)
-  # SSE 单行最大字节数（默认 10MB）
-  max_line_size: 10485760
+  # SSE max line size in bytes (default: 25MB)
+  # SSE 单行最大字节数（默认 25MB）
+  max_line_size: 26214400
   # Log upstream error response body summary (safe/truncated; does not log request content)
   # 记录上游错误响应体摘要（安全/截断；不记录请求内容）
   log_upstream_error_body: false
diff --git a/deploy/config.example.yaml b/deploy/config.example.yaml
index 49bf0afa..40fab16e 100644
--- a/deploy/config.example.yaml
+++ b/deploy/config.example.yaml
@@ -154,9 +154,9 @@ gateway:
   # Stream keepalive interval (seconds), 0=disable
   # 流式 keepalive 间隔（秒），0=禁用
   stream_keepalive_interval: 10
-  # SSE max line size in bytes (default: 10MB)
-  # SSE 单行最大字节数（默认 10MB）
-  max_line_size: 10485760
+  # SSE max line size in bytes (default: 25MB)
+  # SSE 单行最大字节数（默认 25MB）
+  max_line_size: 26214400
   # Log upstream error response body summary (safe/truncated; does not log request content)
   # 记录上游错误响应体摘要（安全/截断；不记录请求内容）
   log_upstream_error_body: false