diff --git a/IRaCIS.Core.API/Controllers/UploadDownLoadController.cs b/IRaCIS.Core.API/Controllers/UploadDownLoadController.cs
index 3fef559d1..31ba365a1 100644
--- a/IRaCIS.Core.API/Controllers/UploadDownLoadController.cs
+++ b/IRaCIS.Core.API/Controllers/UploadDownLoadController.cs
@@ -1077,9 +1077,6 @@ namespace IRaCIS.Core.API.Controllers
                                     // 获取 Pixel Data 标签
                                     var pixelData = DicomPixelData.Create(dicomFile.Dataset);
 
-                                    var frag = dicomFile.Dataset.GetDicomItem<DicomOtherByteFragment>(DicomTag.PixelData);
-
-                                    var originOffsetTable = frag.OffsetTable;
                                     //获取像素是否为封装形式
                                     var syntax = dicomFile.Dataset.InternalTransferSyntax;
 
@@ -1095,7 +1092,12 @@ namespace IRaCIS.Core.API.Controllers
                                             newFragments.Fragments.Add(new MemoryByteBuffer(frameData.Data));
                                         }
 
-                                        newFragments.OffsetTable.AddRange(originOffsetTable.ToArray());
+
+                                        var frag = dicomFile.Dataset.GetDicomItem<DicomOtherByteFragment>(DicomTag.PixelData);
+
+                                        var originOffsetTable = frag?.OffsetTable;
+
+                                        newFragments.OffsetTable.AddRange(originOffsetTable?.ToArray());
                                         // 替换原有的片段序列
                                         dicomFile.Dataset.AddOrUpdate(newFragments);
                                     }
@@ -1286,9 +1288,7 @@ namespace IRaCIS.Core.API.Controllers
                                     // 获取 Pixel Data 标签
                                     var pixelData = DicomPixelData.Create(dicomFile.Dataset);
 
-                                    var frag = dicomFile.Dataset.GetDicomItem<DicomOtherByteFragment>(DicomTag.PixelData);
-
-                                    var originOffsetTable = frag.OffsetTable;
+         
                                     //获取像素是否为封装形式
                                     var syntax = dicomFile.Dataset.InternalTransferSyntax;
 
@@ -1304,7 +1304,11 @@ namespace IRaCIS.Core.API.Controllers
                                             newFragments.Fragments.Add(new MemoryByteBuffer(frameData.Data));
                                         }
 
-                                        newFragments.OffsetTable.AddRange(originOffsetTable.ToArray());
+                                        var frag = dicomFile.Dataset.GetDicomItem<DicomOtherByteFragment>(DicomTag.PixelData);
+
+                                        var originOffsetTable = frag?.OffsetTable;
+
+                                        newFragments.OffsetTable.AddRange(originOffsetTable?.ToArray());
                                         // 替换原有的片段序列
                                         dicomFile.Dataset.AddOrUpdate(newFragments);
                                     }