According to the preliminary borehole ground stress test data, the multiple linear regression analysis theory is used to invert the initial ground stress of the underground cavern group plant area. The results of the ground stress field inversion are in line with the characteristics of the tectonic stress and self-weight stress of the region in terms of overall rules and magnitude. It can be used as a reasonable load condition for subsequent numerical simulation research. According to the layered excavation and support design scheme of the underground cavern group, the three-dimensional elastoplastic finite difference method is used to numerically simulate the construction process of the underground cavern. It analyze the overall stability of the surrounding rock of the underground cavern group, so as to provide a reference basis for the engineering excavation and support design.