diff --git a/internal/app/app.go b/internal/app/app.go
index 1e967b2e..0f6a2f10 100644
--- a/internal/app/app.go
+++ b/internal/app/app.go
@@ -664,6 +664,7 @@ func setupRoutes(
 		protected.GET("/messages/:id/process-details", conversationHandler.GetMessageProcessDetails)
 		protected.PUT("/conversations/:id", conversationHandler.UpdateConversation)
 		protected.DELETE("/conversations/:id", conversationHandler.DeleteConversation)
+		protected.POST("/conversations/:id/delete-turn", conversationHandler.DeleteConversationTurn)
 		protected.PUT("/conversations/:id/pinned", groupHandler.UpdateConversationPinned)
 
 		// 对话分组
diff --git a/internal/database/conversation.go b/internal/database/conversation.go
index bd7bd97f..db180a94 100644
--- a/internal/database/conversation.go
+++ b/internal/database/conversation.go
@@ -4,6 +4,7 @@ import (
 	"database/sql"
 	"encoding/json"
 	"fmt"
+	"strings"
 	"time"
 
 	"github.com/google/uuid"
@@ -553,6 +554,102 @@ func (db *DB) GetMessages(conversationID string) ([]Message, error) {
 	return messages, nil
 }
 
+// turnSliceRange 根据任意一条消息 ID 定位「一轮对话」在 msgs 中的 [start, end) 下标区间（msgs 须已按时间升序，与 GetMessages 一致）。
+// 一轮 = 从某条 user 消息起，至下一条 user 之前（含中间所有 assistant）。
+func turnSliceRange(msgs []Message, anchorID string) (start, end int, err error) {
+	idx := -1
+	for i := range msgs {
+		if msgs[i].ID == anchorID {
+			idx = i
+			break
+		}
+	}
+	if idx < 0 {
+		return 0, 0, fmt.Errorf("message not found")
+	}
+	start = idx
+	for start > 0 && msgs[start].Role != "user" {
+		start--
+	}
+	if start < len(msgs) && msgs[start].Role != "user" {
+		start = 0
+	}
+	end = len(msgs)
+	for i := start + 1; i < len(msgs); i++ {
+		if msgs[i].Role == "user" {
+			end = i
+			break
+		}
+	}
+	return start, end, nil
+}
+
+// DeleteConversationTurn 删除锚点所在轮次的全部消息（用户提问 + 该轮助手回复等），并清空 last_react_*，避免与消息表不一致。
+func (db *DB) DeleteConversationTurn(conversationID, anchorMessageID string) (deletedIDs []string, err error) {
+	msgs, err := db.GetMessages(conversationID)
+	if err != nil {
+		return nil, err
+	}
+	start, end, err := turnSliceRange(msgs, anchorMessageID)
+	if err != nil {
+		return nil, err
+	}
+	if start >= end {
+		return nil, fmt.Errorf("empty turn range")
+	}
+	deletedIDs = make([]string, 0, end-start)
+	for i := start; i < end; i++ {
+		deletedIDs = append(deletedIDs, msgs[i].ID)
+	}
+
+	tx, err := db.Begin()
+	if err != nil {
+		return nil, fmt.Errorf("begin tx: %w", err)
+	}
+	defer func() { _ = tx.Rollback() }()
+
+	ph := strings.Repeat("?,", len(deletedIDs))
+	ph = ph[:len(ph)-1]
+	args := make([]interface{}, 0, 1+len(deletedIDs))
+	args = append(args, conversationID)
+	for _, id := range deletedIDs {
+		args = append(args, id)
+	}
+	res, err := tx.Exec(
+		"DELETE FROM messages WHERE conversation_id = ? AND id IN ("+ph+")",
+		args...,
+	)
+	if err != nil {
+		return nil, fmt.Errorf("delete messages: %w", err)
+	}
+	n, err := res.RowsAffected()
+	if err != nil {
+		return nil, err
+	}
+	if int(n) != len(deletedIDs) {
+		return nil, fmt.Errorf("deleted count mismatch")
+	}
+
+	_, err = tx.Exec(
+		`UPDATE conversations SET last_react_input = NULL, last_react_output = NULL, updated_at = ? WHERE id = ?`,
+		time.Now(), conversationID,
+	)
+	if err != nil {
+		return nil, fmt.Errorf("clear react data: %w", err)
+	}
+
+	if err := tx.Commit(); err != nil {
+		return nil, fmt.Errorf("commit: %w", err)
+	}
+
+	db.logger.Info("conversation turn deleted",
+		zap.String("conversationId", conversationID),
+		zap.Strings("deletedMessageIds", deletedIDs),
+		zap.Int("count", len(deletedIDs)),
+	)
+	return deletedIDs, nil
+}
+
 // ProcessDetail 过程详情事件
 type ProcessDetail struct {
 	ID             string    `json:"id"`
diff --git a/internal/database/conversation_turn_test.go b/internal/database/conversation_turn_test.go
new file mode 100644
index 00000000..68743468
--- /dev/null
+++ b/internal/database/conversation_turn_test.go
@@ -0,0 +1,39 @@
+package database
+
+import (
+	"testing"
+)
+
+func TestTurnSliceRange(t *testing.T) {
+	mk := func(id, role string) Message {
+		return Message{ID: id, Role: role}
+	}
+	msgs := []Message{
+		mk("u1", "user"),
+		mk("a1", "assistant"),
+		mk("u2", "user"),
+		mk("a2", "assistant"),
+	}
+	cases := []struct {
+		anchor string
+		start  int
+		end    int
+	}{
+		{"u1", 0, 2},
+		{"a1", 0, 2},
+		{"u2", 2, 4},
+		{"a2", 2, 4},
+	}
+	for _, tc := range cases {
+		s, e, err := turnSliceRange(msgs, tc.anchor)
+		if err != nil {
+			t.Fatalf("anchor %s: %v", tc.anchor, err)
+		}
+		if s != tc.start || e != tc.end {
+			t.Fatalf("anchor %s: got [%d,%d) want [%d,%d)", tc.anchor, s, e, tc.start, tc.end)
+		}
+	}
+	if _, _, err := turnSliceRange(msgs, "nope"); err == nil {
+		t.Fatal("expected error for missing id")
+	}
+}
diff --git a/internal/handler/agent.go b/internal/handler/agent.go
index e0ecafb4..871df57c 100644
--- a/internal/handler/agent.go
+++ b/internal/handler/agent.go
@@ -1256,7 +1256,7 @@ func (h *AgentHandler) AgentLoopStream(c *gin.Context) {
 
 	// 保存用户消息：有附件时一并保存附件名与路径，刷新后显示、继续对话时大模型也能从历史中拿到路径
 	userContent := userMessageContentForStorage(req.Message, req.Attachments, savedPaths)
-	_, err = h.db.AddMessage(conversationID, "user", userContent, nil)
+	userMsgRow, err := h.db.AddMessage(conversationID, "user", userContent, nil)
 	if err != nil {
 		h.logger.Error("保存用户消息失败", zap.Error(err))
 	}
@@ -1275,6 +1275,14 @@ func (h *AgentHandler) AgentLoopStream(c *gin.Context) {
 		assistantMessageID = assistantMsg.ID
 	}
 
+	// 尽早下发消息 ID，便于前端在流式结束前挂上「删除本轮」等（无需等整段结束再刷新）
+	if userMsgRow != nil {
+		sendEvent("message_saved", "", map[string]interface{}{
+			"conversationId": conversationID,
+			"userMessageId":  userMsgRow.ID,
+		})
+	}
+
 	// 创建进度回调函数，复用统一逻辑
 	progressCallback := h.createProgressCallback(conversationID, assistantMessageID, sendEvent)
 
diff --git a/internal/handler/conversation.go b/internal/handler/conversation.go
index f0c074f0..4bb72bbe 100644
--- a/internal/handler/conversation.go
+++ b/internal/handler/conversation.go
@@ -190,3 +190,44 @@ func (h *ConversationHandler) DeleteConversation(c *gin.Context) {
 	c.JSON(http.StatusOK, gin.H{"message": "删除成功"})
 }
 
+// DeleteTurnRequest 删除一轮对话（POST /api/conversations/:id/delete-turn）
+type DeleteTurnRequest struct {
+	MessageID string `json:"messageId"`
+}
+
+// DeleteConversationTurn 删除锚点消息所在轮次（从该轮 user 到下一轮 user 之前），并清空 last_react_*。
+func (h *ConversationHandler) DeleteConversationTurn(c *gin.Context) {
+	conversationID := c.Param("id")
+	if conversationID == "" {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "conversation id required"})
+		return
+	}
+
+	var req DeleteTurnRequest
+	if err := c.ShouldBindJSON(&req); err != nil || req.MessageID == "" {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "messageId required"})
+		return
+	}
+
+	if _, err := h.db.GetConversation(conversationID); err != nil {
+		c.JSON(http.StatusNotFound, gin.H{"error": "对话不存在"})
+		return
+	}
+
+	deletedIDs, err := h.db.DeleteConversationTurn(conversationID, req.MessageID)
+	if err != nil {
+		h.logger.Warn("删除对话轮次失败",
+			zap.String("conversationId", conversationID),
+			zap.String("messageId", req.MessageID),
+			zap.Error(err),
+		)
+		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
+		return
+	}
+
+	c.JSON(http.StatusOK, gin.H{
+		"deletedMessageIds": deletedIDs,
+		"message":           "ok",
+	})
+}
+
diff --git a/internal/handler/multi_agent.go b/internal/handler/multi_agent.go
index 4ff6b7f6..d8a54625 100644
--- a/internal/handler/multi_agent.go
+++ b/internal/handler/multi_agent.go
@@ -103,6 +103,13 @@ func (h *AgentHandler) MultiAgentLoopStream(c *gin.Context) {
 	conversationID := prep.ConversationID
 	assistantMessageID := prep.AssistantMessageID
 
+	if prep.UserMessageID != "" {
+		sendEvent("message_saved", "", map[string]interface{}{
+			"conversationId": conversationID,
+			"userMessageId":  prep.UserMessageID,
+		})
+	}
+
 	progressCallback := h.createProgressCallback(conversationID, assistantMessageID, sendEvent)
 
 	baseCtx, cancelWithCause := context.WithCancelCause(context.Background())
diff --git a/internal/handler/multi_agent_prepare.go b/internal/handler/multi_agent_prepare.go
index 60244117..4e2ea4fe 100644
--- a/internal/handler/multi_agent_prepare.go
+++ b/internal/handler/multi_agent_prepare.go
@@ -19,6 +19,7 @@ type multiAgentPrepared struct {
 	FinalMessage       string
 	RoleTools          []string
 	AssistantMessageID string
+	UserMessageID      string
 }
 
 func (h *AgentHandler) prepareMultiAgentSession(req *ChatRequest) (*multiAgentPrepared, error) {
@@ -109,9 +110,14 @@ func (h *AgentHandler) prepareMultiAgentSession(req *ChatRequest) (*multiAgentPr
 	finalMessage = appendAttachmentsToMessage(finalMessage, req.Attachments, savedPaths)
 
 	userContent := userMessageContentForStorage(req.Message, req.Attachments, savedPaths)
-	if _, err = h.db.AddMessage(conversationID, "user", userContent, nil); err != nil {
-		h.logger.Error("保存用户消息失败", zap.Error(err))
-		return nil, fmt.Errorf("保存用户消息失败: %w", err)
+	userMsgRow, uerr := h.db.AddMessage(conversationID, "user", userContent, nil)
+	if uerr != nil {
+		h.logger.Error("保存用户消息失败", zap.Error(uerr))
+		return nil, fmt.Errorf("保存用户消息失败: %w", uerr)
+	}
+	userMessageID := ""
+	if userMsgRow != nil {
+		userMessageID = userMsgRow.ID
 	}
 
 	assistantMsg, aerr := h.db.AddMessage(conversationID, "assistant", "处理中...", nil)
@@ -129,5 +135,6 @@ func (h *AgentHandler) prepareMultiAgentSession(req *ChatRequest) (*multiAgentPr
 		FinalMessage:       finalMessage,
 		RoleTools:          roleTools,
 		AssistantMessageID: assistantMessageID,
+		UserMessageID:      userMessageID,
 	}, nil
 }