Abstract. Due to the large computation quantity of laser propagation simulation in complicated laser systems, the traditional serial simulation cannot fulfill the requirement. In this paper, the laser propagation algorithms of coherent light source and noncoherent light source were introduced, two parallel computing modes (parallelization among multi beams and parallelization in one noncoherent beam) were proposed, and a type of data allocation algorithm for load balancing was designed. These were all implemented in EasyLaser which is the component-based laser system simulation software built by us. It has the abilities of fast building parallel simulation programs and can reduce the difficulty to develop parallel programs. In the final, some performance tests for parallel computing were performed on a typical laser propagation simulation model. The test results indicate that the applying of the parallel algorithms can effectively take advantage of the hardware resources and reduce the time consuming.