This thesis obtained the mechanical parameters of rock specimens through rock mechanics tests on a rock sample in a mining area in Jiangxi and applied the Hoek-Brown Criterion to estimate the rock mass mechanical parameters. Combining the fractal theory and the Monte Carlo method, a jointed rock mass network was generated, and jointed rock mass simulation specimens were taken by using the center of the jointed rock mass network as the base point. The discrete element software UDEC was used to stimulate the numerical experiment of the jointed rock mass compressive strength. The results show that controlling for the sampling angle and confining pressure, the increase in rock mass size correlates with the weakening of the anisotropy of the jointed rock mass. The compressive strength of the jointed rock mass shows a non-linear decrease trend and tends to a certain value, which can be fitted into a negative exponential change relationship; controlling for the confining pressure and size, the increase in the sampling angle will result in a slight fluctuation of the compressive strength of the jointed rock mass, which can be explained by the fractal characteristics of the joint distribution. The size effect and confining pressure effect of the jointed rock mass are more obvious when the sampling angle is at 60°, where the compressive strength value is slightly higher; when sampling angle and size are controlled for, as the confining pressure increases, the anisotropy of the rock mass weakens, demonstrating a linear increase in compressive strength.