diff --git a/backend/internal/service/account_stats_pricing.go b/backend/internal/service/account_stats_pricing.go
index 8d5bc144fcad..af82bc15d64d 100644
--- a/backend/internal/service/account_stats_pricing.go
+++ b/backend/internal/service/account_stats_pricing.go
@@ -62,29 +62,17 @@ func resolveAccountStatsCost(
 }
 
 // tryModelFilePricing 使用模型定价文件（LiteLLM/fallback）中的价格计算费用。
+// 与用户计费共用同一条定价管线，避免这里维护第二份"单价 × token 数"实现后，
+// 每加一个定价特性都要手工镜像一次。channelPricing 为 nil，保持优先级 3 的
+// 语义：只取模型定价文件，不引入渠道自定义定价。
 func tryModelFilePricing(billingService *BillingService, model string, tokens UsageTokens, serviceTier string) *float64 {
-	pricing, err := billingService.GetModelPricing(model)
-	if err != nil || pricing == nil {
-		return nil
-	}
-	normalizedTier := normalizeBillingServiceTier(serviceTier)
-	if normalizedTier == "priority" || normalizedTier == "fast" || normalizedTier == "flex" ||
-		billingService.shouldApplySessionLongContextPricing(tokens, pricing) {
-		breakdown, err := billingService.CalculateCostWithServiceTier(model, tokens, 1, normalizedTier)
-		if err != nil || breakdown == nil || breakdown.TotalCost <= 0 {
-			return nil
-		}
-		return &breakdown.TotalCost
-	}
-	cost := float64(tokens.InputTokens)*pricing.InputPricePerToken +
-		float64(tokens.OutputTokens)*pricing.OutputPricePerToken +
-		float64(tokens.CacheCreationTokens)*pricing.CacheCreationPricePerToken +
-		float64(tokens.CacheReadTokens)*pricing.CacheReadPricePerToken +
-		float64(tokens.ImageOutputTokens)*pricing.ImageOutputPricePerToken
-	if cost <= 0 {
+	breakdown, err := billingService.CalculateCostWithServiceTier(
+		model, tokens, 1, normalizeBillingServiceTier(serviceTier),
+	)
+	if err != nil || breakdown == nil || breakdown.TotalCost <= 0 {
 		return nil
 	}
-	return &cost
+	return &breakdown.TotalCost
 }
 
 // tryCustomRules 遍历自定义规则，按数组顺序先命中为准。
diff --git a/backend/internal/service/account_stats_pricing_test.go b/backend/internal/service/account_stats_pricing_test.go
index 1bd28896fcba..84ca0897eccc 100644
--- a/backend/internal/service/account_stats_pricing_test.go
+++ b/backend/internal/service/account_stats_pricing_test.go
@@ -594,8 +594,9 @@ func TestTryModelFilePricing_WithImageOutput(t *testing.T) {
 	}
 	result := tryModelFilePricing(bs, "claude-sonnet-4", tokens, "")
 	require.NotNil(t, result)
-	// 100*0.001 + 50*0.002 + 10*0.01 = 0.1 + 0.1 + 0.1 = 0.3
-	require.InDelta(t, 0.3, *result, 1e-12)
+	// ImageOutputTokens 是 OutputTokens 的子集，先扣除再按图片单价计。
+	// 100*0.001 + (50-10)*0.002 + 10*0.01 = 0.1 + 0.08 + 0.1 = 0.28
+	require.InDelta(t, 0.28, *result, 1e-12)
 }
 
 func TestTryModelFilePricing_WithCacheTokens(t *testing.T) {