A physical model of Xingzi-Hushan section of the North Lake of Poyang Lake is established，to study whether the navigable flow condition of Poyang Lake Water Control Project meets the navigable safety，including the experimental study on navigable flow condition of the current channel of the first stage cofferdam，the design channel of the second stage cofferdam and the operation period of Poyang Lake water control project under different conditions.Firstly，physical model tests are conducted to verify whether there are bad flow patterns in the channel.Secondly，the corresponding optimization measures are studied for the bad flow patterns.Finally，the navigable flow condition in the optimized channel is tested to ensure the safe navigation.The conclusions are as follows：The navigable flow condition of the design channel of the second cofferdam and the the operation period has some problems under the condition of large flow rate，such as the transverse velocity of the upstream entrance area exceeds the limit and large scale backflow is generated in the downstream anchorage.The flow conditions of the designed channel can meet the navigation safety requirements under all conditions by adjusting the form of upstream separation levee，excavating the shoal on the right side of the channel，and moving down the downstream anchorage，etc.