Abstract: By establishing a suitable water pollution warning model, the timely and reliable water pollution warning information is given, which has played guiding role in the prevention and control of water pollution. In this paper, a single factor water pollution index warning model is constructed using the data of single water quality factor and its maximum standard allowable value, which solves the unification of evaluation. The weights of water quality factors were obtained by analytic hierarchy process. Based on the weight and single factor water pollution index, the warning model of water pollution comprehensive index is constructed. The two water pollution warning models were applied in the Lijiang River Basin. The results obtained that the water quality status of the Lijiang River basin was the best as predicted from the dissolved oxygen, permanganate index, and ammonia nitrogen and total phosphorus single factor water quality pollution index. The water quality of the Lijiang River basin was moderate or mild pollution as predicted from total Nitrogen Single Factor Water Pollution Index. The comprehensive water quality of the predicted value of the comprehensive water pollution index was gradually getting better.