Relying on the project of "Integrated Protection and Restoration Project of Mountains, rivers, Forests, fields, Lakes, grass and Sand in Liaohe River Basin (Huntai River System)", a water environment assessment system combining principal component analysis, hierarchical clustering, water quality identification index and inverse distance weight interpolation method was established for the upstream restoration area of Huntai River Basin.The principal component analysis method was used to reduce the dimension and screen the indicators, and the variance test was conducted on the selected indicators. The 173 monitoring points were grouped by cluster analysis and differentiation, and the water quality index method was used to evaluate the mean value of each group after grouping, and then the results were assigned to the corresponding monitoring points. Based on the method of combining watershed scale and administrative division, the water environment assessment and zoning of the study area were carried out, and the water environment of the upper reaches of Huntai River basin were obtained by inverse distance interpolation.The results showed that: (1) The 173 monitoring sites were divided into 14 groups, one group was in class Ⅳ water quality, one group was in poor class Ⅴ water quality, and the remaining 12 groups were in class Ⅲ water quality. Taking Hunhe River Basin and Taizihe River basin as the big boundary, the Hunhe River basin was separated into five evaluation areas, and the Taizihe River basin was divided into four evaluation areas, six of which were in class Ⅲ; (2) The water quality of the upper Huntai Basin is good, only the Qinghe River in the Taizi River Basin and the Daliu River in the Hunhe River Basin are in class Ⅳ, and the Lishi River and Guchengzi River basin in the Hunhe River Basin are in class Ⅴ, and the rest are in class Ⅲ.(3) Qinghe River and Daliu River were mainly BOD5 exceeding the standard, while Lishi River and Guchengzi River were all exceeding the standard because of metal cadmium.The identification and assessment of water environment zones at the watershed scale can break the boundaries of administrative regions in the previous water environment assessment, so as to comprehensively grasp the water environment status of the watershed by taking small and medium-sized watersheds as units.This study can provide a basis for water environment governance in the upper reaches of Huntai River Basin, and the established research ideas and results can also provide a reference for water environment assessment in other basins.