针对高功率激光装置对多程放大器腔镜准直的要求，利用小孔的像传递和光路自动准直的原理，设计出一套创新的腔镜准直调整方法，并且在SG-Ⅲ原型装置4程放大模拟实验平台上进行了实验验证。实验结果表明：自动准直系统能够在15 min之内顺利完成主放大级系统的光路调整，光束近场调整精度值小于近场光斑直径的0.5%，光束远场调整精度小于0.3"。

Alignment accuracy of the cavity mirror in multipass amplifier is very high. Aiming at the requirements on alignment precision of cavity mirror in high power lasers, using image relaying of pinholes and the principle of beam automatic alignment, a scheme to align the cavity mirror is designed. It has been demonstrated on the simulation experiment system of the SG-Ⅲ prototype facility. The main amplifier's adjustment can be finished in 15min. The centering precision of the system is less than 0.5% of the beam diameter. The pointing precision of the system are less than 0.3".