Based on cluster analysis and factor analysis, the hydrochemical characteristics and influencing factors of water samples from 27 lakes in southern Tibet Plateau were studied. The results of cluster analysis showed that the lake hydrochemical parameters were spatially different due to the zonality of climatic conditions and the diversity of lake supply sources. The 27 water samples could be divided into 2 clusters and 5 sub-clusters, and their hydrochemical types were consistent with the evolution process of the lake. The results of factor analysis showed that the hydrochemical characteristics and influencing factors of different types of lakes were different. The main chemical type of fresh water lake was Na-HCO₃. Two factors were extracted to reveal the influence of the dissolution of carbonate and silicate minerals, and the dissolution of sulfate minerals and salt. The main hydrochemical type of saltwater lake is Na-SO₄. Three factors were extracted, which revealed the dissolution of carbonate minerals, the dissolution of sulfate minerals and salt, and the influence of human activities on the hydrochemical characteristics of salt lake. The main hydrochemical type of saline is Na-Cl, and two factors were extracted, which revealed the influence of the dissolution of rock salt minerals and silicate minerals, and the dissolution of sulfate minerals and carbonate minerals on the hydrochemistry of saline.