Togngu rapids is a curved branch shoal-rapids which is characterized by dangerous navigation. The regulation of Xu-Lu section has solved the problem of navigation obstruction of Tonggu rapids. Based on the model test result and according to the engineering effect, we research the water-sediment characteristics of navigation-obstruction features, and probe into the regulation idea and measures for the rapids. The main flow of the rapids tends straight at the flood and falls in the bay in the dry season. In the flood season the upper flow and lower flow are separated and the upper flow tends straight, the lower flow brings mud and turns to the bending area. We can dig narrow deep straight channel assisted with regulation buildings in river to guarantee the channel stability; Considering the separation law of water and sand, we should determine proper diversion point to make water run through the straight channel while sand goes through the bending channel.