The junction located at the branch entrance of tidal river is always close to the main river due to limited land conditions,so the branch mouth flow is significantly affected by the tidal flow of the main river，and the flow pattern is complex.Thus engineering problems such as siltation,bank erosion,cross flow exceeding standard in approach channel,etc. appear easily at the entrance area.Therefore,a step structural form of levee head was designed to improve the flow condition.The results of the physical model tests show that the angle between the main river flow and pilot river flow decreases,and the erosion of river bank and the cross flow in the approach channel on the flood tide diversion case decrease as well.Meanwhile,the increase of the area of water flow and the decrease of river erosion lead to the reduction of recirculation range,which is conductive to the stability of river in the drainage tide ebb.