diff --git a/MonitorModule/ViewModels/MonitorViewModel.cs b/MonitorModule/ViewModels/MonitorViewModel.cs
index f2d1bee..4843448 100644
--- a/MonitorModule/ViewModels/MonitorViewModel.cs
+++ b/MonitorModule/ViewModels/MonitorViewModel.cs
@@ -222,10 +222,8 @@ namespace MonitorModule.ViewModels
 
             if (channel == null) return;
 
-            double time = _stopwatch.Elapsed.TotalSeconds;
-
             // 记录数据点（线程安全：Record 内部 ConcurrentQueue + Series 操作）
-            channel.Record(time, args.Value);
+            channel.Record(args.Time, args.Value);
 
             // 入队数据库批量写入
             // CreateTime 使用 args.Time（采样触发时刻），而不是 DateTime.Now（设备响应到达时刻），
@@ -252,13 +250,12 @@ namespace MonitorModule.ViewModels
         {
             if (!_stopwatch.IsRunning) return;
 
-            double elapsed = _stopwatch.Elapsed.TotalSeconds;
+            var now = DateTime.Now;
             var xAxis = Plot.Axes.FirstOrDefault(a => a.Position == AxisPosition.Bottom);
             if (xAxis != null)
             {
-                double window = 10000 * 0.1; // 20s 视窗
-                xAxis.Minimum = Math.Max(0, elapsed - window);
-                xAxis.Maximum = elapsed + 0.5;
+                xAxis.Minimum = DateTimeAxis.ToDouble(now.AddSeconds(-20));
+                xAxis.Maximum = DateTimeAxis.ToDouble(now.AddSeconds(0.5));
             }
             Plot.InvalidatePlot(true);
         }
@@ -370,10 +367,11 @@ namespace MonitorModule.ViewModels
                 PlotAreaBorderColor = OxyColors.LightGray,
                 Background = OxyColors.White
             };
-            pm.Axes.Add(new LinearAxis
+            pm.Axes.Add(new DateTimeAxis
             {
                 Position = AxisPosition.Bottom,
-                Title = "时间 (s)",
+                Title = "时间",
+                StringFormat = "HH:mm:ss",
                 MajorGridlineStyle = LineStyle.Dot,
                 MinorGridlineStyle = LineStyle.None
             });
@@ -822,7 +820,7 @@ namespace MonitorModule.ViewModels
                     var recent = channel.DataPoints.ToArray();
                     var startIdx = Math.Max(0, recent.Length - 10000);
                     for (int i = startIdx; i < recent.Length; i++)
-                        channel.Series.Points.Add(new DataPoint(recent[i].Time, recent[i].DisplayValue));
+                        channel.Series.Points.Add(new DataPoint(recent[i].Time.ToOADate(), recent[i].DisplayValue));
 
                     Plot.Series.Add(channel.Series);
                     Plot.InvalidatePlot(true);
@@ -846,7 +844,7 @@ namespace MonitorModule.ViewModels
             channel.Series.Points.Clear();
             var startIdx = Math.Max(0, points.Length - 10000);
             for (int i = startIdx; i < points.Length; i++)
-                channel.Series.Points.Add(new DataPoint(points[i].Time, points[i].DisplayValue));
+                channel.Series.Points.Add(new DataPoint(points[i].Time.ToOADate(), points[i].DisplayValue));
             Plot.InvalidatePlot(true);
         }
         #endregion
diff --git a/UIShare/UIViewModel/MonitorChannel.cs b/UIShare/UIViewModel/MonitorChannel.cs
index 02bcdc0..514c553 100644
--- a/UIShare/UIViewModel/MonitorChannel.cs
+++ b/UIShare/UIViewModel/MonitorChannel.cs
@@ -1,5 +1,6 @@
 using OxyPlot.Series;
 using OxyPlot;
+using System;
 using System.Collections.Concurrent;
 using Prism.Mvvm;
 using NCalc;
@@ -52,7 +53,7 @@ namespace UIShare.UIViewModel
 
         // ===== 数据存储 =====
         /// <summary>所有采样数据点（线程安全），与 OxyPlot 无关</summary>
-        public ConcurrentQueue<(double Time, double RawValue, double DisplayValue)> DataPoints { get; } = new();
+        public ConcurrentQueue<(DateTime Time, double RawValue, double DisplayValue)> DataPoints { get; } = new();
 
         /// <summary>最大缓冲数据点数，超出则丢弃最旧的</summary>
         public int MaxBuffer { get; set; } = 5000;
@@ -67,7 +68,7 @@ namespace UIShare.UIViewModel
 
         // ===== 辅助方法 =====
         /// <summary>记录一个数据点：RawValue 经数学变换后得到 DisplayValue，一并入队</summary>
-        public void Record(double time, double rawValue)
+        public void Record(DateTime time, double rawValue)
         {
             double displayValue = rawValue;
 
@@ -82,7 +83,7 @@ namespace UIShare.UIViewModel
             // 如果正在显示，同步到 Series
             if (_series != null)
             {
-                _series.Points.Add(new DataPoint(time, displayValue));
+                _series.Points.Add(new DataPoint(time.ToOADate(), displayValue));
                 while (_series.Points.Count > 10000)
                 {
                     _series.Points.RemoveAt(0);