Abstract:The water quality of the river basin is directly related to human health and ecological safety. Taking section from Xiangyanghu to Heyanqiao of the Pingshui River as the research object, its spatial characteristics of water quality were analyzed, four methods were used to evaluate water quality, and multivariate statistical method and level difference method were applied to comparatively analyze the results of four commonly used assessment methods. The results show that: 1) The highest concentrations of COD, NH3-N, TP and TN are found at the sampling point No.11 (near Chishanqiao); water qualities of upstream (Xiangyang Lake-Qiaotoucun village) and downstream (Chishanqiao bridge-Heyanqiao bridge) are relatively good. Contents of TN, Fe and Mn in some sampling points slightly exceed standards, pollution degree in the middle area (Qiaotoucun village-Chishanqiao bridge) is significantly weaker than other areas. 2) The worst water quality grade is class Ⅴ or inferior class Ⅴ, with pollution degree of serious pollution and more than serious pollution; single factor evaluation method determines TN as the main pollution index, principal component analysis identifies two principal components, which can be interpreted as nutrient pollution index and geological sedimentary environment index. 3) There is a significant positive correlation between four methods, and correlation coefficients vary from 0.937 to 0.994, but it shows an obvious difference in the water quality level. The results of level difference method show that water quality grades of three comprehensive water quality evaluation methods are listed in order as follows: Nemerow pollution index method < comprehensive pollution index method < principal component analysis method. The results can provide reference for the related work and research of water quality assessment in the basin, and provide scientific basis for the development and utilization of water resources, water environment protection and comprehensive treatment in the basin.