Abstract: The evolution of the water environment process under the interference of human activities is a difficult problem facing global water security. As an important influence area and water source area of the South-to-North Water Diversion Middle Route Project, the Hanjiang River has experienced frequent blooms under the dual influence of climate change and human activities in the past ten years. The implementation of water pollution prevention and control policies has important practical significance. Based on 7 main water quality indicators including (pH, ρ(DO), ρ(COD_Mn), ρ(BOD₅), ρ(NH₃-N), ρ(TP), ρ(TN))of 448 groups of continuous monitoring data from 8 monitoring stations in middle and downstream of Hanjiang River from 2011 to 2018, the temporal and spatial evolution characteristics of water quality in middle and downstream of Hanjiang River were analyzed by using seasonal Mankendall test, correlation analysis and redundancy analysis, and the correlation between land use types and water quality changes was analyzed. The results show that: (1) In terms of time characteristics, the overall water quality of the middle and downstream of Hanjiang River showed an improvement trend from 2011 to 2018. The concentration of pollutants in the high water period was higher than that in the low water period, and peaked in 2013-2014. The water quality gradually improved after 2015. (2) In terms of spatial characteristics, the water quality gradually deteriorated from the middle reaches to the downstream reaches of Hanjiang River. Due to the opening of the water diversion project from the Yangtze River to the Hanjiang River in 2014, the water quality of Luohanzha station and downstream improved. (3) In general, farmland and urban land are significantly positively correlated with pollutant concentration, with a maximum degree of interpretation of 0.27, forestland, grassland and pollutant concentration were significantly negatively correlated, with a maximum degree of interpretation of 0.31. Studies have shown that the water quality in middle and downstream of Hanjiang River has improved, and farmland and urban land have a greater impact on the deterioration of the water quality in middle and downstream of Hanjiang River. Vegetation cover such as forest land and grassland can reduce water pollution to some extent due to their water conservation function and natural purification capacity.