In order to study the dam break flow in mountain river, SPH method was used to solve the dam break flow model based on the two dimensional shallow water equations. Since the Lagrangian SPH method has good stability and accuracy in dealing with convection dominated problems and is meshfree method, there is no need to divide the grid and to determine the wet-dry grid, therefore it well resolves the issues that mountain river dam break flow velocity is acute, water level range is large, moving boundary changes frequently, and the calculation region is difficult to determine. The model was used to simulate the mountain river dam break flow and preliminarily represents the dam break flow process. The analysis showed that the simulation results are reasonable and the SPH method is feasible to simulate the dam break flow.
