Abstract: Compared with inland areas, the urban tidal river network faces greater pressure in terms of flood and waterlog control and water environment protection. The use of tidal range for inland river diversion and drainage by the sluices along outer river is an effective way to enhance the flood control and drainage capacity of tidal river network and improve its water environment quality. However, the development of riverside industries along outer river is in contradiction with the water diversion and drainage of tidal river network. For arguing the new construction of Huisheng Heavy Industry 3# Outfitting Wharf near the gate of Nantong Farm Sluice, in this research, mathematical models were used to investigate the influence of the outfitting wharf project on the diversion and drainage of tidal river network, and a generalization of ship into movable gate was proposed. The equivalent treatment method for the analysis of the water blocking effect of the ship and its rationality were verified. It is concluded that the widening of the dredging measures at the entrance of the outfitting wharf project are beneficial to the drainage of the tidal river network, but are not good for the water diversion of the tidal river network. Ship mooring at the entrance has little effect on the diversion and drainage of the tidal river network.