A parallel smoothed molecular dynamies (SMD) method is proposed. Parallel programs with SMD and SMD-MD coupling are developed for loading problems of a plate with a crack and a nano single crystal copper beam subjected to remote tensile. With traditional molecular dynamics, smoothed molecular dynamics method introduces fixed background mesh and solves motion equations. Critical time step in SMD is controlled by background grid size and could be enlarged to save simulation time. Results are in agreement with those of traditional molecular dynamics. Compared with traditional MD simulation, SMD and SMD-MD coupling methods save computing time.