Abstract: The principle of total light scattering method is introduced in this paper, the influence of different wavelengths on the correlation degree of vectors in extinction coefficient matrix was analyzed, and soft measurement model of mine dust size distribution information is established. We propose incident wavelength selection method within the range of full spectral characteristics, which overcomes the disadvantage of low efficiency of traditional single band within the scope of the incident waves. We design experimental platform of mine dust particle size distribution measurement for total light scattering, compare mine dust particle size distribution measurement results, and verify the feasibility and accuracy of this method.