Based on fractal theory,the cluster-cluster aggregation (CCA) model is used to simulate the fractal structure of the soot agglomerates with random distribution,and the properties of single scattering of randomly distributed soot agglomerates are studied using the discrete dipole approximation (DDA) method.Then the laser attenuation characteristics in the randomly distributed soot cluster agglomerates are studied using Monto Carlo method.The effects of the incident angle,laser wavelength,number concentration,the number and diameter of primary particles in soot agglomerates on the attenuation properties of laser are discussed.The research result provides theoretical basis to the propagation and attenuation characteristics of laser in the complex random medium.