粒度反演算法是基于米氏散射理论的激光粒度仪的关键技术。针对独立模式迭代反演算法对噪声太敏感，以至于在实际应用中出现粒度测量失真的问题，提出采用5点3次数据平滑算法对其反演进行处理，同时以VISUAL C++6.0为开发平台，编写测试软件对算法进行仿真研究，并与粒度真实分布进行了对比。结果表明，特征粒径D10，D90的误差分布小于5%，D50的误差分布小于3%，说明数据平滑处理后的反演结果能够反映粒度的真实分布，解决了探测光能误差使粒度测量结果失真的难题，基本满足了现代粉体工业粒度测量的精度高、抗干扰性能强、稳定可靠等要求。

Particle size inverse algorithm is the key technology for laser particle size analyzer based on Mie theory. Because the independent model iterative inverse algorithm was so sensitive to noise that it can not be used in actual particle size measurement, five-spot triple smoothing algorithm was proposed to conduct independent model iterative inversion. With VISUAL C++6.0 as development platform, the software was written and simulation was carried out. The simulation result was compared with actual distribution. The distribution error of special particle size D10, D90 was less than 5%, and the distribution error of special particle size D50 was less than 3%. The results show that only the inversion data after smoothing processing can reveal the actual distribution of particle size. The inversion result distortion induced by the optical energy detection error can be overcome. This algorithm can satisfy the requirements of high accuracy, anti-jamming and stability for particle size measurement in modern power industry.