数值模拟研究大气湍流的核心问题是构造准确且计算量小的大气湍流相位屏，以正确反映折射率的变化特性。根据大气湍流统计特性，采用分形方法数值模拟了方形大气湍流相位屏。对模拟结果进行统计分析，并与结构函数理论值对比，得到符合Kolmogorov统计规律的大气湍流相位分布。以此为基础，分析了分形法模拟大气湍流相位屏的性能。结果表明，分形法生成的方形相位屏在统计特性上与理论值基本吻合，从低频、中频到高频部分，由于分形迭代次数的增加，误差累加，相位屏模拟误差增大。随着相位屏采样点数量的增加，相位屏的模拟精度降低，同时所需模拟的相位屏数量增加。随着相位屏数量的增加，不同强度的大气湍流相位屏模拟精度趋于相似。

Phase screen can reflect the change of refractive index correctly. Constructing an accurate atmospheric turbulence phase screen with small calculation amount is the key of numerical simulation. According to the statistical characteristics of turbulence, square atmospheric turbulence phase screen is calculated using fractal model. The simulation results complying with Kolmogorov atmospheric turbulence are obtained by analyzing the simulation results and theoretical values of phase structure function. Performance of atmospheric turbulence phase screen simulation based on fractal method is also analyzed. Analysis results show that square atmospheric turbulence phase screen simulation based on fractal method is consistent with the theoretical values in statistical properties. The simulation error of phase screen increases with fractal iterations from the area of low-frequency to the one of high-frequency. With the increasing grid numbers of phase screen, the accuracy of phase screen simulation is reduced. Besides, the number of phase screen needed is increased. As the number of phase screens increases, the simulation accuracies of atmospheric turbulence phase screens with different intensities turn similar.