The downstream reach of Minjiang River is a natural channel,which has typical characteristics of mountain river.The waterway deteriorates seriously because of complicated obstacle property and sand excavation in the past years.Aiming at navigation obstructing problem of the shallow,sharp,curved and dangerous of Bawang rapids,we establish a two-dimensional water mathematical model,analyze the rapids characteristics and cause of formation,and determine the rational scheme through the comparison and optimization of multiple schemes considering the improvement degree of navigation flow condition,stability of channel and hydraulic parameter of rapids abating,and propose the regulation principle,concept and corresponding measures of similar mountain river rapids.The results show that the overall stability and trenching stability of the modified scheme 1-1 are better,and the work quantity is smaller than other schemes,so it is the recommended regulation scheme.