Water environmental capacity is the basis and core of regional total pollutant control, providing an important scientific basis for water ecological management in the basin. Previous studies mostly focused on the dynamic changes of water environmental capacity in different hydrological periods, but did not consider the seasonal characteristics of point and non-point sources into the river. The method of analytical formula is used to determine the water environmental capacity of the Taige canal under the combined influence of point and non-point sources pollution characteristics. Then,MIKE 11 is used to construct a mathematical model of water volume and water quality in the hydrological catchment area of the Taige canal, so as to simulate the water quality standard of typical sections under the condition of maximum allowable discharge.The research shows that the environmental capacity of the canal is COD of 22 694.52 t·a-1, NH3-N of 854.04 t·a-1 and TP of 195.58 t·a-1. All the typical sections can achieve the water quality target of water function zoning, and the calculation method is reasonable and feasible.