Random variation in temperature field causes refractive index fluctuation in the atmosphere. Wind velocity affects atmosphere turbulence dynamic characteristic. Thus, it forms optical turbulence effects and influences atmospheric laser transmission. Based on this principle, a modified Herriott type of long-optical-path atmospheric turbulence simulator for studies of atmospheric propagation characteristics is proposed. It can simulate the temperature difference (ΔT ) ranging with 10~200 ℃ , wind velocity with 0~5.8 m/s and optical path with 1~100 m for the random atmospheric turbulence. Measurement and analysis of the laser propagation beam quality influence at different ΔT and wind speeds are completed. Experimental results reveal that the performance of this simulator is almost identical with actual situation. It possesses wide ΔT , optional optical path, good repeatability, highly precise, etc. Therefore, it meets the needs of atmospheric turbulence effect experiment.