diff --git a/backend/internal/config/config.go b/backend/internal/config/config.go
index a7780096..e3dc2109 100644
--- a/backend/internal/config/config.go
+++ b/backend/internal/config/config.go
@@ -1117,9 +1117,8 @@ type DefaultConfig struct {
 }
 
 type RateLimitConfig struct {
-	OverloadCooldownMinutes     int `mapstructure:"overload_cooldown_minutes"`       // 529过载冷却时间(分钟)
-	RateLimit429CooldownSeconds int `mapstructure:"rate_limit_429_cooldown_seconds"` // 429无重置时间时的默认回避时间(秒)
-	OAuth401CooldownMinutes     int `mapstructure:"oauth_401_cooldown_minutes"`      // OAuth 401临时不可调度冷却(分钟)
+	OverloadCooldownMinutes int `mapstructure:"overload_cooldown_minutes"`  // 529过载冷却时间(分钟)
+	OAuth401CooldownMinutes int `mapstructure:"oauth_401_cooldown_minutes"` // OAuth 401临时不可调度冷却(分钟)
 }
 
 // APIKeyAuthCacheConfig API Key 认证缓存配置
@@ -1579,7 +1578,6 @@ func setDefaults() {
 
 	// RateLimit
 	viper.SetDefault("rate_limit.overload_cooldown_minutes", 10)
-	viper.SetDefault("rate_limit.rate_limit_429_cooldown_seconds", 5)
 	viper.SetDefault("rate_limit.oauth_401_cooldown_minutes", 10)
 
 	// Pricing - 从 model-price-repo 同步模型定价和上下文窗口数据（固定到 commit，避免分支漂移）
diff --git a/backend/internal/service/rate_limit_429_cooldown_test.go b/backend/internal/service/rate_limit_429_cooldown_test.go
index 35206454..fb7e0dd7 100644
--- a/backend/internal/service/rate_limit_429_cooldown_test.go
+++ b/backend/internal/service/rate_limit_429_cooldown_test.go
@@ -97,10 +97,9 @@ func TestHandle429_FallbackDisabledSkipsLocalMark(t *testing.T) {
 	require.Zero(t, accountRepo.rateLimitCalls)
 }
 
-func TestHandle429_FallbackUsesConfigSecondsWhenSettingServiceMissing(t *testing.T) {
+func TestHandle429_FallbackUsesDefaultSecondsWhenSettingServiceMissing(t *testing.T) {
 	accountRepo := &rateLimit429AccountRepoStub{}
 	cfg := &config.Config{}
-	cfg.RateLimit.RateLimit429CooldownSeconds = 9
 	svc := NewRateLimitService(accountRepo, nil, cfg, nil, nil)
 
 	account := &Account{ID: 44, Platform: PlatformGemini, Type: AccountTypeAPIKey}
@@ -110,5 +109,5 @@ func TestHandle429_FallbackUsesConfigSecondsWhenSettingServiceMissing(t *testing
 
 	require.Equal(t, 1, accountRepo.rateLimitCalls)
 	require.Equal(t, int64(44), accountRepo.lastRateLimitID)
-	require.True(t, !accountRepo.lastRateLimitReset.Before(before.Add(9*time.Second)) && !accountRepo.lastRateLimitReset.After(after.Add(9*time.Second)))
+	require.True(t, !accountRepo.lastRateLimitReset.Before(before.Add(5*time.Second)) && !accountRepo.lastRateLimitReset.After(after.Add(5*time.Second)))
 }
diff --git a/backend/internal/service/ratelimit_service.go b/backend/internal/service/ratelimit_service.go
index 293fc528..a53cb0e9 100644
--- a/backend/internal/service/ratelimit_service.go
+++ b/backend/internal/service/ratelimit_service.go
@@ -955,9 +955,6 @@ func (s *RateLimitService) get429FallbackCooldown(ctx context.Context, account *
 	}
 
 	seconds := defaultRateLimit429CooldownSeconds
-	if s.cfg != nil && s.cfg.RateLimit.RateLimit429CooldownSeconds > 0 {
-		seconds = s.cfg.RateLimit.RateLimit429CooldownSeconds
-	}
 	seconds = clampRateLimit429CooldownSeconds(seconds)
 	return time.Duration(seconds) * time.Second, true
 }
diff --git a/deploy/config.example.yaml b/deploy/config.example.yaml
index 04ebd795..1670699b 100644
--- a/deploy/config.example.yaml
+++ b/deploy/config.example.yaml
@@ -948,10 +948,6 @@ rate_limit:
   # 上游返回 529（过载）时的冷却时间（分钟）
   overload_cooldown_minutes: 10
 
-  # Default cooldown time (in seconds) when upstream returns 429 without a reset time
-  # 上游返回 429 且无明确重置时间时的默认回避时间（秒）
-  rate_limit_429_cooldown_seconds: 5
-
 # =============================================================================
 # Pricing Data Source (Optional)
 # 定价数据源（可选）