diff --git a/backend/internal/api/handlers/billing.go b/backend/internal/api/handlers/billing.go
index 610bb1a..a179a8f 100644
--- a/backend/internal/api/handlers/billing.go
+++ b/backend/internal/api/handlers/billing.go
@@ -4,7 +4,6 @@ import (
 	"fmt"
 	"net/http"
 	"sort"
-	"strings"
 	"time"
 
 	"ezops/internal/models"
@@ -306,171 +305,3 @@ func (h *BillingHandler) checkBillingAlerts(stats *models.BillingStats, now time
 		}
 	}
 }
-
-// ListAlertRules 获取预警规则列表
-func (h *BillingHandler) ListAlertRules(c *gin.Context) {
-	var rules []models.BillingAlertRule
-	h.db.Order("created_at DESC").Find(&rules)
-
-	c.JSON(http.StatusOK, models.Response{
-		Code:    200,
-		Message: "success",
-		Data: models.ListResponse{
-			List:  rules,
-			Total: int64(len(rules)),
-		},
-	})
-}
-
-// CreateAlertRule 创建预警规则
-func (h *BillingHandler) CreateAlertRule(c *gin.Context) {
-	var req models.CreateBillingAlertRequest
-	if err := c.ShouldBindJSON(&req); err != nil {
-		c.JSON(http.StatusBadRequest, models.Response{Code: 400, Message: err.Error()})
-		return
-	}
-
-	rule := models.BillingAlertRule{
-		Name:           req.Name,
-		Provider:       req.Provider,
-		CloudAccountID: req.CloudAccountID,
-		Metric:         req.Metric,
-		Threshold:      req.Threshold,
-		Operator:       req.Operator,
-		Enabled:        req.Enabled,
-	}
-	if rule.Metric == "" {
-		rule.Metric = "daily"
-	}
-	if rule.Operator == "" {
-		rule.Operator = ">"
-	}
-
-	if err := h.db.Create(&rule).Error; err != nil {
-		c.JSON(http.StatusInternalServerError, models.Response{Code: 500, Message: "创建失败"})
-		return
-	}
-
-	c.JSON(http.StatusOK, models.Response{
-		Code:    200,
-		Message: "创建成功",
-		Data:    rule,
-	})
-}
-
-// UpdateAlertRule 更新预警规则
-func (h *BillingHandler) UpdateAlertRule(c *gin.Context) {
-	id := c.Param("id")
-	var rule models.BillingAlertRule
-	if err := h.db.First(&rule, id).Error; err != nil {
-		c.JSON(http.StatusNotFound, models.Response{Code: 404, Message: "规则不存在"})
-		return
-	}
-
-	var req models.CreateBillingAlertRequest
-	if err := c.ShouldBindJSON(&req); err != nil {
-		c.JSON(http.StatusBadRequest, models.Response{Code: 400, Message: err.Error()})
-		return
-	}
-
-	rule.Name = req.Name
-	rule.Provider = req.Provider
-	rule.CloudAccountID = req.CloudAccountID
-	rule.Metric = req.Metric
-	rule.Threshold = req.Threshold
-	rule.Operator = req.Operator
-	rule.Enabled = req.Enabled
-	if rule.Metric == "" {
-		rule.Metric = "daily"
-	}
-	if rule.Operator == "" {
-		rule.Operator = ">"
-	}
-
-	h.db.Save(&rule)
-
-	c.JSON(http.StatusOK, models.Response{
-		Code:    200,
-		Message: "更新成功",
-		Data:    rule,
-	})
-}
-
-// DeleteAlertRule 删除预警规则
-func (h *BillingHandler) DeleteAlertRule(c *gin.Context) {
-	id := c.Param("id")
-	if err := h.db.Delete(&models.BillingAlertRule{}, id).Error; err != nil {
-		c.JSON(http.StatusInternalServerError, models.Response{Code: 500, Message: "删除失败"})
-		return
-	}
-	c.JSON(http.StatusOK, models.Response{Code: 200, Message: "删除成功"})
-}
-
-// ToggleAlertRule 启用/禁用预警规则
-func (h *BillingHandler) ToggleAlertRule(c *gin.Context) {
-	id := c.Param("id")
-	var rule models.BillingAlertRule
-	if err := h.db.First(&rule, id).Error; err != nil {
-		c.JSON(http.StatusNotFound, models.Response{Code: 404, Message: "规则不存在"})
-		return
-	}
-
-	rule.Enabled = !rule.Enabled
-	h.db.Save(&rule)
-
-	status := "已启用"
-	if !rule.Enabled {
-		status = "已禁用"
-	}
-
-	c.JSON(http.StatusOK, models.Response{
-		Code:    200,
-		Message: status,
-		Data:    rule,
-	})
-}
-
-// GetProviderOptions 获取厂商选项（用于筛选下拉）
-func (h *BillingHandler) GetProviderOptions(c *gin.Context) {
-	var providers []string
-	h.db.Model(&models.CloudBilling{}).Distinct("provider").Where("provider != ''").Pluck("provider", &providers)
-
-	result := make([]gin.H, 0, len(providers))
-	for _, p := range providers {
-		label := p
-		switch p {
-		case "aliyun":
-			label = "阿里云"
-		case "tencent":
-			label = "腾讯云"
-		case "aws":
-			label = "AWS"
-		case "huawei":
-			label = "华为云"
-		case "azure":
-			label = "Azure"
-		}
-		result = append(result, gin.H{"value": p, "label": label})
-	}
-
-	c.JSON(http.StatusOK, models.Response{
-		Code:    200,
-		Message: "success",
-		Data:    result,
-	})
-}
-
-// formatProvider 格式化厂商名称
-func formatProvider(provider string) string {
-	names := map[string]string{
-		"aliyun":  "阿里云",
-		"tencent": "腾讯云",
-		"aws":     "AWS",
-		"huawei":  "华为云",
-		"azure":   "Azure",
-	}
-	if name, ok := names[strings.ToLower(provider)]; ok {
-		return name
-	}
-	return provider
-}
diff --git a/backend/internal/api/handlers/billing_alert.go b/backend/internal/api/handlers/billing_alert.go
new file mode 100644
index 0000000..7493972
--- /dev/null
+++ b/backend/internal/api/handlers/billing_alert.go
@@ -0,0 +1,168 @@
+package handlers
+
+import (
+	"net/http"
+	"strings"
+
+	"ezops/internal/models"
+
+	"github.com/gin-gonic/gin"
+)
+
+// 本文件从 billing.go 拆分而来，承载账单预警规则域 CRUD // Logan.Li
+// 与 BillingHandler 共享 receiver，同 package 无需修改 routes.go
+
+// ListAlertRules 获取预警规则列表 // Logan.Li
+func (h *BillingHandler) ListAlertRules(c *gin.Context) {
+	var rules []models.BillingAlertRule
+	h.db.Order("created_at DESC").Find(&rules)
+
+	c.JSON(http.StatusOK, models.Response{
+		Code:    200,
+		Message: "success",
+		Data: models.ListResponse{
+			List:  rules,
+			Total: int64(len(rules)),
+		},
+	})
+}
+
+// CreateAlertRule 创建预警规则 // Logan.Li
+func (h *BillingHandler) CreateAlertRule(c *gin.Context) {
+	var req models.CreateBillingAlertRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, models.Response{Code: 400, Message: err.Error()})
+		return
+	}
+
+	rule := models.BillingAlertRule{
+		Name:           req.Name,
+		Provider:       req.Provider,
+		CloudAccountID: req.CloudAccountID,
+		Metric:         req.Metric,
+		Threshold:      req.Threshold,
+		Operator:       req.Operator,
+		Enabled:        req.Enabled,
+	}
+	if rule.Metric == "" {
+		rule.Metric = "daily"
+	}
+	if rule.Operator == "" {
+		rule.Operator = ">"
+	}
+
+	if err := h.db.Create(&rule).Error; err != nil {
+		c.JSON(http.StatusInternalServerError, models.Response{Code: 500, Message: "创建失败"})
+		return
+	}
+
+	c.JSON(http.StatusOK, models.Response{
+		Code:    200,
+		Message: "创建成功",
+		Data:    rule,
+	})
+}
+
+// UpdateAlertRule 更新预警规则 // Logan.Li
+func (h *BillingHandler) UpdateAlertRule(c *gin.Context) {
+	id := c.Param("id")
+	var rule models.BillingAlertRule
+	if err := h.db.First(&rule, id).Error; err != nil {
+		c.JSON(http.StatusNotFound, models.Response{Code: 404, Message: "规则不存在"})
+		return
+	}
+
+	var req models.CreateBillingAlertRequest
+	if err := c.ShouldBindJSON(&req); err != nil {
+		c.JSON(http.StatusBadRequest, models.Response{Code: 400, Message: err.Error()})
+		return
+	}
+
+	rule.Name = req.Name
+	rule.Provider = req.Provider
+	rule.CloudAccountID = req.CloudAccountID
+	rule.Metric = req.Metric
+	rule.Threshold = req.Threshold
+	rule.Operator = req.Operator
+	rule.Enabled = req.Enabled
+	if rule.Metric == "" {
+		rule.Metric = "daily"
+	}
+	if rule.Operator == "" {
+		rule.Operator = ">"
+	}
+
+	h.db.Save(&rule)
+
+	c.JSON(http.StatusOK, models.Response{
+		Code:    200,
+		Message: "更新成功",
+		Data:    rule,
+	})
+}
+
+// DeleteAlertRule 删除预警规则 // Logan.Li
+func (h *BillingHandler) DeleteAlertRule(c *gin.Context) {
+	id := c.Param("id")
+	if err := h.db.Delete(&models.BillingAlertRule{}, id).Error; err != nil {
+		c.JSON(http.StatusInternalServerError, models.Response{Code: 500, Message: "删除失败"})
+		return
+	}
+	c.JSON(http.StatusOK, models.Response{Code: 200, Message: "删除成功"})
+}
+
+// ToggleAlertRule 启用/禁用预警规则（服务端自动翻转） // Logan.Li
+func (h *BillingHandler) ToggleAlertRule(c *gin.Context) {
+	id := c.Param("id")
+	var rule models.BillingAlertRule
+	if err := h.db.First(&rule, id).Error; err != nil {
+		c.JSON(http.StatusNotFound, models.Response{Code: 404, Message: "规则不存在"})
+		return
+	}
+
+	rule.Enabled = !rule.Enabled
+	h.db.Save(&rule)
+
+	status := "已启用"
+	if !rule.Enabled {
+		status = "已禁用"
+	}
+
+	c.JSON(http.StatusOK, models.Response{
+		Code:    200,
+		Message: status,
+		Data:    rule,
+	})
+}
+
+// GetProviderOptions 获取厂商选项（用于筛选下拉） // Logan.Li
+func (h *BillingHandler) GetProviderOptions(c *gin.Context) {
+	var providers []string
+	h.db.Model(&models.CloudBilling{}).Distinct("provider").Where("provider != ''").Pluck("provider", &providers)
+
+	result := make([]gin.H, 0, len(providers))
+	for _, p := range providers {
+		result = append(result, gin.H{"value": p, "label": formatProvider(p)})
+	}
+
+	c.JSON(http.StatusOK, models.Response{
+		Code:    200,
+		Message: "success",
+		Data:    result,
+	})
+}
+
+// formatProvider 格式化厂商名称 // Logan.Li
+func formatProvider(provider string) string {
+	names := map[string]string{
+		"aliyun":  "阿里云",
+		"tencent": "腾讯云",
+		"aws":     "AWS",
+		"huawei":  "华为云",
+		"azure":   "Azure",
+	}
+	if name, ok := names[strings.ToLower(provider)]; ok {
+		return name
+	}
+	return provider
+}