The 2D tidal current and sediment mathematical model is built with FVM to Qitai breakwater in Lianyungang to study the changing of tide,tidal current and suspend sediment concentration nearby the port after completion of the breakwater,so as to provide technical support for future development of Lianyungang port.Accompanying the completion of Qitai breakwater,the nature of tide is altered neighboring the port and the tidal current is weakened in the harbor district but strengthened in the breakwater gap,the water with high suspend sediment concentration is away from the breakwater and the maximum sediment concentration in the harbor district is reduced.