Understanding and predicting laser beam propagation effects in the atmosphere is important for laser applications. Turbulence effects cause beam wander, beam broadening, intensity scintillations, which reducing the power in bucket and the tracking accuracy, etc. In this work, the phase screens are used to model atmosphere turbulence in the model of the laser propagation through troposphere. And according to the characteristics of the troposphere，a layered model is used. Laser propagation follows the Huygens-Fresnel principle between phase screens. Simulations with different grid point numbers were constructed, and numerical experiments were conducted. According to the simulated results including Strehl ratio, sharpness, and amplitude distribution, preceding phase screens have effect on the total energy of the receiving surface, but have little impact on amplitude distribution. And the phase screens, which are close to the receiving surface, have a significant impact on both amplitude distribution and the total receiving energy. The results suggests that in simulation one should increase grid point numbers as many as possible and needs to pay particular attention to parameters of the phase screens near the receiving surface in simulation.