基于米氏散射原理的激光粒度仪是颗粒测量领域应用最广泛的仪器之一。通常情况下颗粒越小，散射角越大，激光粒度仪探测器阵列接收到的散射光能分布的主峰位置越靠外。但是，对特定相对折射率的颗粒，在某些粒径区间，散射光能分布的主峰位置会随着颗粒粒径的减小而向探测器阵列的内侧移动，称之为散射光能分布的反常移动。根据米氏散射原理，给出了反常移动的规律以及不同相对折射率下反常移动的粒径区间，分析了反常移动对粒度分析的影响，提出了降低该影响的方法，并对实际样品进行测试对比。结果表明，该方法可以降低反常移动对粒度分析的影响。

Laser particle sizer which based on Mie scattering theory is one of the most widely used instruments in particle size measurement. Generally the smaller the particles are, the bigger the scattering angle is. The main peak position of Mie scattered energy distribution received by the detector array moves outward. However, for some particles of relative index of refraction in certain size ranges, the main peak position of scattered energy distribution moves toward the inside of the detector array as the particle size decreases, which can be called the abnormal moving of scattered energy distribution. Based on Mie scattering theory, the patterns of such abnormal moving and abnormal particle size interval of different relative indexes of refraction are obtained, the effect on particle size analysis is analysed, a method to reduce the effect is proposed. An actual sample is measured and compared. The results show that this method can reduce the effect of abnormal moving on particle size analysis.