Abstract: The 3 existing geothermal wells in Pingyin of Shandong Province are rich in physiotherapy mineral elements, with high physiotherapy value. Based on the hydrochemical and isotopic analysis data from previons works, the authors in this paper dissected hydrochemical characteristics, recharge source, formation age and water-rock interaction process of geothermal water, and estimated the temperature of heat storage, the proportion of cold water mixing proportions and the depth of hot water circulation. The results show that the hydrochemical types of geothermal water in the study area are all Cl·CO₄-Na·Ca, and the source of water recharge is atmospheric precipitation, with the supply elevation of 274~277 m. The apparent age of ¹⁴C in geothermal water samples is 15.81~7.01 ka, indicating the mixed water is dominated by the ancient water. The occurrence of geothermal water was in different concealed base fault zones, but the solute component of geothermal water mainly comes from the dissolution of silicate minerals, meaning the similar hydrogeochemical process. The geothermal reservoir temperature calculated by chalcedony temperature is 46.2~54.4 ℃, while the geothermal reservoir temperature estimated by Si-enthalpy model is about 121~122 ℃, with cold water mixing proportion of about 0.76~0.88. The circulation depth of geothermal water is 1 428~5 139 m.