Abstract: The lower Yellow River reach from Huayuankou to Jiahetan is a typical wandering river. The generation of computational mesh,which is used to simulate the flood,is affected by the distribution of water works in the river channel. The spatial information about the two Yellow River banks,the protecting dykes,and these roads that is obviously higher than the ground are need to be used to generate the computational mesh. As a result these dykes and roads must be located in the element interface of the computational mesh. In the model the finite-volume method is used to solve the shallow wave equations and the Osher scheme is used to calculate the flux through the interface between the neighbor element. The flood event with peak discharge of 15 300 m³/s,occurred in the period from July 30 to August 10,1982,is simulated1 The estimated result indicates that the simulation method is good.