The Fengnan 100，000 DWT channel of Tangshan Port is based on the expansion of a 20，000 DWT channel.The channel flow condition is complicated,and navigation condition is bad,so the design of the channel is very difficult.Based on the analysis of the tide duration and selection of tide level,we determine the main scale of the navigation channel and propose a reasonable channel layout scheme,which is further optimized in combination with the real ship test.Based on the numerical simulation test of current,we determine the window period of navigation.After the demonstration,it is recommended that the layout type of plan No.1 should be adopted.When a 100，000 DWT ship rides through the entrance by tide,it is the time of still tide,the flow speed is small,and the flow is stable,which is the best navigation opportunity and is conducive to the safe navigation of ships.When a large ship is influenced by the cross flow or the flow state of the entrance is complex through the port,the synchronous relationship between the high tide level and the large cross flow should be taken into consideration.