断面法和输沙率法是两种简便的测淤方法，也是我国目前所广泛采用的两种确定冲淤数量的方法。在潼关至三门峡河段，这两种方法测验结果相差较大，已引起人们的普遍重视。对这两种测量方法的可靠性有些人已作了对比分析，但是对造成断面法与输沙率法测量成果偏离的主要原因深入分析不够。本文通过对三门峡库区潼关以下河道两种测淤成果的对比分析，得出产生偏离的原因。 Cross section method and sediment transport rate method are two simple method of measuring silt, but also the two currently widely used method to determine the amount of scour and silting. In the Tongguan to Sanmenxia reach, the difference between the two methods test results, has aroused widespread attention. Some of the reliability of these two measurement methods have been comparative analysis, but the main reason for the deviation of the cross-sectional method and sediment transport method results is not enough in-depth analysis. This article through Sanmenxia reservoir area under the Tongguan two kinds of siltation results comparative analysis of the cause of the deviation generated.