Laser Shock Processing (LSP) is a kind of new surface hardening technology, which can increase fatigue life obviously. Due to the LSP, the residual stress is generated and dislocations increase obviously in the surface of specimen, so the fatigue life of specimen processed by LSP increases. Thanks to the finite element programs, it is able to simulate the fatigue life. The simulation of fatigue life has important significance, which not only can reduce the costs of fatigue test and research, but also further study the effect of LSP on fatigue life. The results of fatigue test coincide with the results of simulation.