先简单介绍了蒙特卡洛方法的基本知识与应用领域，然后详细地介绍了多次散射，并强调了多次散射在干扰中的重要作用。针对红外烟幕对红外辐射有较强的吸收和散射作用，利用蒙特卡洛方法，模拟了红外在红外烟幕中的传输过程，并给出了具体实现算法；并利用了散射相位函数确定了散射角。最后通过实验验证了接收视场角的大小影响单次散射近似范围。

Firstly the basic information and application field of Monte Carlo method are introduced in this paper, then multiple scattering is introduced in details, and the importance of multiple scattering is emphasized. Because of absorption and scattering characteristics of smoke screen, infrared radiation through smoke screen is simulated by means of Monte Carlo method. And scattering corner is decided by means of scattering phase function. At last, the experiment result indicates that the field of view affects the approximate range of single scattering.