diff --git a/utils/chat.js b/utils/chat.js
index 38243b5..89b70e8 100644
--- a/utils/chat.js
+++ b/utils/chat.js
@@ -106,7 +106,7 @@ export function formatChatShowTime(sendDate) {
  */
 export function scrollToBottomByContentHeight(
   vm,
-  { selector = ".chat-content", extraOffset = 200 } = {}
+  { selector = ".chat-content", extraOffset = 200 } = {},
 ) {
   if (!vm) return;
 
@@ -154,6 +154,27 @@ export function processChatMessageContent(message) {
   return message;
 }
 
+// 解析 sendDate 为微秒级时间戳（防止毫秒级精度丢失）
+function getSendDateMicroValue(sendDate) {
+  const raw = String(sendDate || "").trim();
+  if (!raw) return Number.NaN;
+  const match = raw.match(/^(.+?)(?:\.(\d+))?(Z|[+-]\d{2}:?\d{2})?$/);
+  if (!match) {
+    const ms = new Date(raw).getTime();
+    return Number.isNaN(ms) ? Number.NaN : ms * 1000;
+  }
+
+  const base = match[1] || "";
+  const fraction = match[2] || "";
+  const zone = match[3] || "";
+  const baseMs = new Date(`${base}${zone}`).getTime();
+  if (Number.isNaN(baseMs)) return Number.NaN;
+
+  const microStr = `${fraction}000000`.slice(0, 6);
+  const microValue = Number(microStr);
+  return baseMs * 1000 + microValue;
+}
+
 /**
  * 聊天消息排序：按 `sendDate` 升序；时间相同时，用户消息（`interactMode=0`）排在前面。
  * 同时会对每条消息的 `message` 字段进行 `processChatMessageContent` 处理。
@@ -169,8 +190,13 @@ export function sortChatMessages(list = []) {
   }));
 
   return processedList.sort((a, b) => {
-    const timeA = new Date(a && a.sendDate).getTime();
-    const timeB = new Date(b && b.sendDate).getTime();
+    const timeA = getSendDateMicroValue(a && a.sendDate);
+    const timeB = getSendDateMicroValue(b && b.sendDate);
+    if (Number.isNaN(timeA) && Number.isNaN(timeB)) {
+      return (a && a.interactMode) - (b && b.interactMode);
+    }
+    if (Number.isNaN(timeA)) return 1;
+    if (Number.isNaN(timeB)) return -1;
     if (timeA === timeB) return (a && a.interactMode) - (b && b.interactMode);
     return timeA - timeB;
   });