Abstract: According to the monitoring data of three major transboundary rivers, namely Xiangshui River, Xiaobai river, Nanbei rivers from 2011 to 2020, The improved Nemerow index method, Spearman rank correlation coefficient method and principal component analysis were used to analyze the water quality and impact factors. The results showed that the overall water quality was good. The water quality ranking was as follows: Xiaobai river >Xiangshui river >Nanbei rivers. According to Spearman rank correlation coefficient analysis, the changes of water quality of Xiangshui River and Nanbei River sections were basically stable. The water quality of Xiaobai River was getting better. The overall annual change trend was not significant, and the overall water quality change was basically stable within the year. According to water quality impact factor analysis, Xiangshui River was mainly composed of BOD, Pb, Cd, and LAS; Nanbe River was mainly composed of CODMn, TP, Zn, As, and LAS; Xiaobai River was mainly composed of BOD, Pb, Cd, As, and LAS.