Discontinuities in rock masses greatly influence stress wave transmission. Before performing numerical modeling on complicated cases, benchmarking modeling must be performed first to validate the numerical code through comparison with theoretical solutions or experiment results. The accuracy of numerical results generally increases with decreasing mesh size. However, with an extremely fine mesh size, substantial computational time will be consumed. 3D plane wave propagation across a single joint or a joint set can be treated equivalently to a corresponding 2D case, as shown both analytically and numerically. However, it should be noted that when the incident wave is not a plane wave or there are unparallel joints and joint sets, a 3D case cannot be equivalent to a 2D case.