Cluster-cluster aggregation model based on Monte Carlo method is used to simulate the structure of the fractal-like soot cluster agglomerates consisting of spherical primary particles，and Mueller-matrix elements of fractal-like soot cluster agglomerates are calculated based on the discrete dipole approximation method. The numerical relations between the Mueller-matrix elements and the total number and the diameter of the primary sphere in agglomerate are discussed for different incident wavelengths，which provides an effective theoretical method for studing the formation mechanism，structural characteristics and scattering characteristics of randomly distributed cluster agglomerates.