设想近江侧筑闸、近海侧敞开的通吕运河经拓宽挖深，通过一维非恒定流数值计算和有关规范，确定运河规划控制尺度，并分析其沿程（全长８１．８ｋｍ）冲淤变化特性．根据小庙洪水道的历史演变和水文泥沙条件，选择蒿枝港以北３ｋｍ处新港闸附近作为通吕运河出海口岸较合适，本文对长江第二入海通道的规划设计具有一定参考价值． Assuming that the dam on the river side is open, the Tonglu canal open on the offshore side is broadened and deepened. Based on the numerical calculation of one-dimensional unsteady flow and relevant norms, the scale of canal planning and control is determined, and the erosion and deposition along its length (81.8km in total length) Change characteristics. According to the historical evolvement of Xiaomiao flood course and the hydrological and sediment conditions, it is more appropriate to choose the vicinity of Xingang gate near 3 km north of Artemisia port as Tonglu canal to go to the sea port. This article is of some reference value for the planning and design of the 2nd channel into the sea.