In order to analyse the in-situ stress characteristics of the underground powerhouse of Shuiyuan mountain pumped storage power station, this paper established a three-dimensional finite element geological model according to the geological conditions of the Pumped Storage Power Station, combined with the measured in-situ stress data by the hydraulic fracturing test, the actual distribution laws of the in-situ stress field in the engineering area of Shuiyuan Mountain Pumped Storage Power Station were obtained. The research results show that: the maximum principal stress distribution state is obviously affected by the topography, the stress concentration phenomenon is manifested at the gully. The maximum principal stress value near the powerhouse ranges from 13.8 MPa to 18.7 MPa, while the minimum principal stress value near the powerhouse ranges from 9.9 MPa to 13.6 MPa. It is also show that the maximum horizontal principal stress value in the project area does not exceed 32.1 MPa. The simulation results of boreholes are in good agreement with the measured results of in-situ stress of each borehole, and the maximum horizontal principal stress direction obtained in the simulation is the NW direction, which is basically in agreement with the measured direction of the maximum principal stress. Those indicate that the results of the simulation results are reliable and can provide a basis for regional in-situ stress analysis and underground powerhouse excavation.