Based on the polarized bidirectional reflectance distribution function ,the scattering fields of Rayleigh defect particle on the optical surface or inlay the substrate were derived to solve the diagnosis of the particle position. By analysis and discussion of bidirectional reflectance distribution function of pp about redundant defect particles with different wavelength , the positions of defect particles were identified preliminary. The results show that the sensing degree of wavelength with particles on the substrate is more than particles on the SiO2 coating. Therefore, the position of defect particle is judged by measuring the sensing degree of wavelength. The angle dent appears between 85° and 90° with the defect particles in the Si substrate, while the angle dent appears around 70° with the defect particles in the SiO2 coating. The angle dent is used to judge the particle position further in the project.