Shicheng is rich in geothermal resources. From the perspective of hydrogeochemistry, we systematically study the evolution mechanism of geothermal water, optimize the target area supporting the blind zone of the geotropics and excavate hidden geothermal water, and promote the sustainable scale of geothermal resources. Development and utilization are of great significance. Based on a full analysis of the geothermal geological conditions of the Shicheng geo- tropical zone, the results of the geothermal and cold water chemical analysis, the Piper three- line diagram, the correlation analysis between solutes, and the geochemical temperature scale method are used to analyze the chemical characteristics and the sources of mineral elements of geothermal water. The source, thermal storage temperature and burial conditions, and the mixing mechanism of shallow cold water were discussed and analyzed. The results show that all the geothermal fields in the Shicheng subtropical zone belong to the same geothermal system. Atmospheric precipitation naturally infiltrates and replenishes in the middle and low mountainous areas of the Yasu Mountain in the northeast. The water- rock interaction enriches mineral elements such as K+, SiO2, and turns to the southwest side to runoff and shallow discharge after encountering the Shicheng fault that blocks water. The quality of geothermal water changes from HCO3- Ca type to SO4- Na type, SO4·HCO3- Na·Ca type, HCO3- Na·Ca type. This zoning is affected by the deep geothermal runoff distance and shallow cold water mixing. The result of joint control of ratio, upwelling path, strata and ore body characteristics.