Qingsong region in Qingpu District is typical tidal plain river network area. The hydrodynamics of the river network is weak, and the river flow moves back and forth. The problem with the current flowing water scheme of diversion water from the west and the south, drainage to the east and the north was diagnosed based on numerical simulation and field test. The flow rate of water diversion from the west is only 10 to 20 m³/s. The river drainage to north could only depend on pumps and influence very limited river region, leading to rivers with low velocity. Based on the hydrodynamics of high water level in the Wusongjiang River and larger tidal range from the Lanlugang River to the Huangpu River, the optimization flowing water scheme of diversion water from the north, drainage to the east, and naturally diversion and drainage in the southwest was proposed. The result indicates that the hydrodynamics of the optimization flowing water scheme is greatly improved, the flow velocity in the main rivers and in the medium and small rivers increases by 27. 5% and 18. 5% respectively. The flow rate of water diversion is also greatly improved, and the total diversion flow of the Xidayinggang River, Dongdayinggang River, Youdungang River and Xintongbotang River reaches 40 m³/s from the Wusongjiang River. The water quality of the main rivers is obviously improved from grade Ⅴ or worse to grade Ⅳ.