Based on interference technology, a cloud particle measurement system is designed. The scattering angle of the system is selected as 90°. The iterative mean filter algorithm is modified, and the system testing using laboratory measurement is completed. The measurement of the spectral distribution of warm cloud particles in a cloud chamber is realized. Similar particle-sized distributions are observed under different pressures, and the particle size is mainly distributed in the range of 5 to 50 µm. The peak appears at particle sizes of 20 to 30 µm. This system features potential applications in cloud microphysics research.