Using the discrete-dipole approximation (DNA) method, after calculating optical characteristics of the single soot aggregation particle, we obtained the relationships of scattering cross section, absorption cross section and asymmetry parameter of soot aggregation particle with the changing incident angles, which provide an efficient approach for the research of radiative transportation of wave in soot particles. We propose the angular distribution of scattering matrix elements of soot particles at different incident angles, which provides a theoretical approach for the research of scattering characteristics, polarization characteristics, and the structural characteristics of the scatterer.