Hanzhuang double way locks shares the approach channel and its filling and discharging will generate unsteady flow in the downstream approach channel.During flood discharge of Hanzhuang sluice and the old canal sluice,the flow conditions of approach channel are more complex.This study uses international general MIKE21 hydrodynamic model to study the longitudinal velocity,transverse velocity and reflux distribution of approach channel,waiting area and entrance of approach channel of the downstream Hanzhuang double way locks.In accordance with the Code for Master design of shiplocks,to solve the problem of hydraulic during flood discharge,this study proposes effective engineering measures for improving the flow conditions.