A hybrid discrete particle swarm optimization(DPSO) algorithm is proposed for heterogeneous parallel system to get the minimal completion time and the optimal load balancing, in which the Sufferage algorithm is introduced to optimize the position and velocity model of DPSO and improve the DPSO ability. Compared with the standard generation algorithm(GA) and single DPSO algorithm, simulation results show that, the modified DPSO is better in efficiency and searching ability and can get a good load balance.