Abstract: In order to improve the accuracy of particle size inversion, eliminate the scattering spectrum noise, the Mie scattering spectrum data of different angles were filtered by one dimensional guided filter, and the characteristics of the guided filter were analyzed. In order to solve the problem of local noise caused by the guidance data, a wavelet-guided filtering algorithm was proposed. The results show that the filtering result is similar to that of the wavelet filter in the small scattering angle, but the filtering effect is better than the wavelet filter in the large scattering angle, and the pulse noise may be filtered out. The result of wavelet-guided joint filtering is the same as that of the guided filter at 15°, the filtering effect is better than that of the wavelet filter or the guided filter at 45° to 90°, and the local noise caused by the guidance data can be removed.