Abstract: The Suzhou river network was taken as an example to explore the influence of hydrodynamic enhancement of urban river network on water environment improvement and evaluate the benefit of water diversion project under the conditions of summer flood season.In this study, by monitoring and analyzing the hydrodynamics and water quality of several rivers under different flow conditions, the improvement effect of hydrodynamics on water quality of the river network was discussed.The results show that under maximum open drainage conditions, the pollutant flux of the Qimen River decreased by 15.2%, the Pingmen river decreased by 16.5%, and the Xueshi River decreased by 13.2%. The north network was more improved than the south one.The enhancement scheme can effectively increase the mobility of the river network. The concentration of COD and dissolved oxygen in the river network water is sensitive under different hydrodynamic conditions, and can be used as a typical water quality index parameter for the river network in the city area, to reflect the influence of hydrodynamic regulation.