Abstract: Based on the hydrochemical data of 2 groups of geothermal water and 3 groups of geothermal water around the area overnight, the genetic mechanism of geothermal water was studied by using hydrochemical, isotopic and geothermal temperature scale methods. The results show that the main source of geothermal water is mantle heat and fault friction heat, and the main source of geothermal water is precipitation and snowmelt water at the elevation of 4 627～4 848.83 m on the west side, the main hydrochemical type is HCO₃-Na, and the main hydrochemical process is the dissolution and cation exchange of silicate minerals, which is consistent with the chemical property of the surrounding hot water. The geothermal water is located on the west side of the Ganzi-litang County Fault. The lithology of the geothermal water is mainly Triassic monzogranite and the sandstone and sandstone slate of the Tumugou Formation, it migrates downward and eastward and meets with the heat source from the mantle at about 3 596～5 508 m underground, forming a deep heat reservoir of 185.7～281.3 ℃, a shallow heat reservoir with a temperature of 69.4～93.8 ℃ is formed by mixing cold water from the surface of the Earth with a temperature of about 1 270～1 758 m, and the mixing ratio is about 77.81%～92.53% . The research results can provide strong support for the development and utilization of geothermal resources in the overnight area.