Abstract: Taking Taicang urban district of typical plain river network area as an example, a water quantity and quality model of one-dimensional river network was established, and the model parameters were calibrated by field water diversion experiment. According to the operation situation of the sluice gate stations in Taicang urban district, eight water diversion schemes were formulated, and the change of water quality before and after water diversion is evaluated by comprehensive water quality identification method,and the optimal scheme is determined.