The light scattering phenomenon of particles is studied, and a Chin-Shifrin transform inversion algorithm for particle size measurement of pulverized coal is proposed. The algorithm uses a linear array CCD as the photodetector, and calculates the scattered light intensity of small-sized particles based on the Fraunhofer diffraction principle. On the basis of analyzing the principle of the algorithm, the calculation formula of the corresponding integral angle interval for inversion is given. Through numerical simulation, the Chin-Shifrin transformation is used to invert the average particle size of 90um pulverized coal particles. The simulation results show that the relative error of particle size distribution measurement is less than 4%.