In this paper, on the basis of laboratory triaxial mechanical experiments, a granite model including different numbers and angles of fractures was established by the discrete element method. Combined with the laboratory triaxial mechanical experiments and PCF simulation results, the effects of the number and angle of fractures on the rock mechanical properties of fractured granite reservoirs were analyzed. The results show that the existence of fractures significantly reduces the strength of the reservoir, but the increase of the fracture angle and the confining pressure will weaken the degree of this reduction, and the fractures are easy to expand and connect during the loading process.