Taking a small watershed of tributaries in Lijiang River as the research object of non-point source pollution,the paper used simplified SWAT model to simulate the loading of non-point source pollution in the demonstration area.By simplifying SWAT model, it established non-point source pollution model which applied to small watershed tributaries in Lijiang River,and. evaluated the applicability of the model and got the conclusion that the relative error (Re) is less than 25%, the correlation coefficient (R2) is larger than 0.7 and Nash-Sutcliffe coefficient of efficiency (Ens) is larger than 0.5.The fitting effect is good. The result indicates that it is feasible to establish the simplified SWAT model in watershed of tributaries in Lijiang River for simulating the non-point source pollution.