According to the data of water quality monitoring in Dianshan lake in 2013, the water quality in Dianshan Lake was evaluated as mild eutrophication. The paper constructed one-dimensional model of river network water quantity and water quality for Dianshan Lake basin and verified the parameters of the model. The results show that by 2020, the environmental capacity of COD will be 13901 t/a, the environmental capacity of NH3—N be 1021 t/a, the environmental capacity of TP be 196 t/a. By combining the calculation results of the maximum allowed volume of pollutants of the water function zones into the river as well as the pollutant flux ratio into river lake, the paper designed the corresponding compliance program of section water quality and proposed suggestions that is to further treat the nonpoint source so as to improve the total phosphorus index. The result can provide theoretical support for the further implementation of comprehensive improvement of water environment in Dianshan Lake basin.