Taking the diversion tunnel of Danba Hydropower Station of Dadu River in Sichuan Province as the research object, we developed the space multi-angle tensile strength test technology and combined with the triaxial test. The mechanical parameters of quartz mica schist under different angles were measured. The relationships between elastic modulus, c, φ and confining pressure of quartz mica schist were obtained，and the order of confining pressure sensitivity rankings of the mechanical parameters under dry and saturated conditions were calculated. By analyzing the anisotropic parameters k1、k2, the relationship between the anisotropy of quartz mica schist and the confining pressure under different angles was evaluated, and the change law of the tensile strength of different heights along with the angle of schistosity was further obtained. Using a transversely isotropic constitutive model and setting the spatial orientation of the material's principal axis, it is possible to simulate the rock mass distributed at any angle in the schistosity space. In view of the deficiencies of the large-area model, this paper proposes a new method for constructing the fine stress field with principal stress, avoiding the stress boundary effect of the large model, and making it possible to perform fine stress construction on the local area quickly and easily. According to the trend of the schistosity and different dip angles, fifteen different schistosity spatial distribution models were selected for calculation and analysis. The changes of the stress, displacement, and plasticity regions with the angles of the schistosity were respectively given, and the worst working conditions under different schistosity distribution were pointed out.