On the basis of the existing researches and the highly effective computational language FORTRAN 95, a practical computer program for simulating laser propagating in the atmosphere was developed. The program, based on the optical field's Maxwell equation and the multiple phase screen method, could numerically simulate the turbulence effects, thermal blooming and their mutual effects for laser atmospheric propagation.Four types of propagation paths and ten kinds of optical turbulence profiles are also included into the program,which make it possible to simulate the propagating process and the atmospheric effects for laser beam With a circular or rectangular aperture under currently available conditions. Moreover, the beam propagating process can be visualized simultaneously by utilizing open graphics library(OpenGL). With the friendly user interface and convenient parameter settings, the program can be widely used for predicting and evaluating the propagation effects in the fields of free space laser communications, lidar detecting and beam propagation investigation in random media.