Comprehensive watershed management is of great significance for wetland water environment improvement and ecological restoration，and hydrodynamic numerical simulation is an important means to predict the restoration effect. Based on the lake morphology，hydrological conditions，landform characteristics and watershed management project of Futou Lake，this paper analyzes the water quality of Futou Lake by Mike 3，establishes the flow field of the lake and carries out the hydrodynamic simulation，compares and analyzes the hydrodynamic characteristics and changes before and after the removal of polders，estimates the impact of the removal of polders on the flow field of the lake，verifies the rationality of the process，and provides reference for the analysis of water quality changes of the whole lake. The effective application of numerical simulation in watershed management and ecological restoration project can optimize the lake ecological restoration scheme as a whole.