The shoal of Maoweihai locates in the interactional area of the river outlet and tidal current,and the waterway development of it faces sophisticated flow and sediment problems.With current physical model,we simulate the whole tidal current,carry out a comparative analysis on the current pattern and current field variation of the waterway to be developed,and calculate the sediment in the waterway.The results show that it is very bad to maintain the waterway for the largest digging depth,the biggest increase of channel flow and the greatest siltation in Wajingjiang channel.It is unsafe to ship navigation for the biggest cross flow in Dalanjiang waterway plan B.In view of problems such as the influence from the tank water of ebb tidal,greater local velocity and sediment deposition,as well as the serious cross flow at the turning part of the waterway,channel development shall choose the deep groove with small cross-flow and may dredge properly.