The modified smoothed particle hydrodynamics method (MSPH) has obvious advantages on simulating the radiation effects of resin composite irradiated by laser, but the serial computation is difficult to meet the demand. In order to improve the computational efficiency of the serial MSPH program, the parallelization of the serial program was carried out by using the message passing interface (MPI) standard. The parallel computing results were compared with the serial computing results given by a personal computer, and the performances of the parallel program involving speed-up and efficiency are tested on a 5 teraflop computer cluster. Numerical calculations show that the parallel computing results are consistent with the serial computing results, thus obtaining a very good parallel performance. Therefore, the parallelization based on MPI is successful.