Aiming at the problem of causes of the obstruction to navigation at the outlet of the Fubei waterway in the lower reaches of the Yangtze River，we study the recent bed evolution，channel maintenance and river type and hydrodynamic characteristics at the outlet section of the Fubei waterway at the river section of Fujiangsha by combining such research techniques as data analysis，channel evolution analysis and model calculation.The results show that the outlet section of the Fubei waterway is subject to such factors as upstream incomings of water and sediment，the weakening of the hydrodynamic force due to the natural relaxation of the river channel and the increase of the resistance to discharge caused by the lateral overbank flow at the tail of the Minzhu Sand，which sometimes leads to the phenomenon of the siltation of obstruction to navigation.It is suggested to take engineering measures to weaken the overbank flow at the tail of the Minzhu Sand in time to reduce the pressure on the maintenance of the Fubei waterway.