In order to reveal the hydrochemical characteristics and influencing factors of surface water in Chating mining area, find out the source of ions and clarify the water quality, 33 surface water samples were collected. The hydrochemical types, material sources and influencing factors of surface water in the study area were analyzed by means of mathematical statistical analysis, hydrochemical graphical method and spatial interpolation. Comprehensive water quality index (WQI) and irrigation water quality assessment were used to evaluate the surface water quality in the study area. The results show that the surface water in the study area was freshwater, weakly alkaline, and its water chemical type was mainly Ca-HCO₃. The water chemical composition is mainly controlled by rock weathering, with little influence from human activities and cation exchange. The chemical composition comes from silicate weathering, carbonate dissolution and sulfate dissolution. The results of WQI drinking evaluation showed that the surface water quality was excellent and reached the drinking standard under certain conditions. Irrigation water quality evaluation results showed that surface water samples could be directly used as irrigation water, and rational utilization will not cause soil salinization.