针对同轴米散射激光雷达，提出了判断出射激光束光轴和望远镜光轴是否同轴的准直判据。以判据最大化为控制目标，以二维电动镜架为执行机构，采用变步长调节算法，设计了同轴米散射激光雷达自准直系统。实验结果表明该系统可实现高精度快速自准直调节，调节精度可达0.05 mrad，验证了准直判据和调节算法的有效性。这有利于实现激光雷达系统的自动化和无人值守。

A criterion is proposed to judge if the axes of the emergent beam and the telescope of coaxial Mie lidar are in the same line. Then the auto collimation system of coaxial Mie lidar is designed, in which the control target aims at the maximization of the criterion, the two-dimension electric driving mirror is used as actuator, and the variable step size regulation algorithm is used. The experiment results show that the system can realize auto collimation regulation with high precision and high speed, and the regulation accuracy is up to 0.05 mrad. The effectiveness of collimation criterion and regulation algorithm is verified. The system is benificial for realizing automation and unattended operation of lidar system.