To investigate the propagation of surface flaws in rocks under dynamic loading, an elastic-plastic ordinary state-based peridynamic model that considers the compressive to tensile strength ratio is used for numerical tests based on the results of previous experiments. The failure process of rocks containing three-dimensional surface flaws at different angles and depths under dynamic loading is simulated. The simulation results show that the peridynamic model used can well simulate the propagation of three-dimensional cracks in rocks and the failure process of specimens. Peridynamic simulations can be used to obtain strength variation regularity which is consistent with the experimental results. The crack generated on the surface of the specimen penetrates to a certain depth inside the specimen, which is related to the depth of the surface flaw. Shell-like cracks generated inside the specimen join with cracks generated on the surface to form complex three-dimensional cracks.