Coal mining activities in arid-semi-arid regions often lead to a series of ecological and environmental problems such as aquifer desiccation, lake shrinkage and disappearance, vegetation decline, and surface desertification. Coal mining drainage is the main driving force that causes the evolution of groundwater-soil-vegetation system. In this paper, based on hydrogeological and ecological vegetation surveys, we used mathematical statistics, linear regression, correlation analysis and other methods to reveal the effects of groundwater level changes on soil characteristics and the response mechanism of surface vegetation under the influence of coal mining activities, taking the Bojianghaizi watershed as an example. The results showed that there was a significant negative correlation between groundwater depth and soil moisture content, soil conductivity, soil organic matter, soil available nitrogen and soil available potassium. Mining activities have led to changes in soil properties, which has greatly weakened its ability to retain water and nutrients. The contents of soil water content, organic matter, available nitrogen and available potassium in the mining area are significantly lower than those in the surrounding areas. There is serious soil salinization in the lakeshore zone where the depth of groundwater table is <0.5m, and the water required for the growth of vegetation here mainly comes from groundwater, so there are only a few kinds of water-loving and saline-resistant plants; when the depth of groundwater is 0.5-7m, the growth of surface vegetation is subjected to the double influence of groundwater and atmospheric precipitation, so the main growth in these areas is semi-dependence on groundwater-type plants. When the depth of groundwater is >7m, it is difficult for groundwater to rise to the root system of vegetation by capillary force, and the main condition for vegetation communities to obtain water is atmospheric precipitation, so drought-tolerant vegetation mainly grows in these areas.