本文利用平面二维水沙数学模型，采用水边界全区自动跟踪方法并考虑了河床局部冲刷与河道演变分析成果，对渠河交叉工程河段进行了洪水与河床变形的数值模拟。模型经过历史特征洪水验证，模拟计算了特征洪水的流场、交叉工程处的壅水及冲刷，根据流场冲刷状况提出了工程优化修改方案。 In this paper, numerical simulation of flood and riverbed deformation is carried out by using the 2D 2D model of water and sediment, the automatic tracking method in the whole water area and taking into account the results of riverbed local scour and river evolution analysis. The model was verified by historical characteristic floods, and the flow field of characteristic floods, sluice and scour of crossing engineering department were calculated and simulated. Based on the situation of flow field erosion, a project optimization and modification plan was proposed.