根据机载激光通信的环境和链路距离，采用光电粗精复合轴结构，提出一种双探测器、双光轴机载激光通信复合轴捕获跟踪瞄准系统方案.对整个系统的光路结构进行了分析和优化设计，使粗跟踪精度达120 μrad，精跟踪系统带宽大于300 Hz，执行动态范围达5 mrad，跟踪精度达3 μrad，并成功实现通信距离17.5 km、通信速率1.5 Gbps，误码率达1E7的飞机对地面激光通信实验.

A dualdetector compoundaxis APT scheme of airborne laser communication is proposed, according to the environment of communication link. The compound axis consists of Coarse Tracking Assembly (CTA) and Fine Tracking Assembly (FTA). A detailed analysis and optimization design of whole optical path structure is carried out. Then a technique about switching between coarse beacon and fine beacon is put forward. This way improves energy density of fine beacon and therefore can make CCD high frame work. Finally, it improves servo bandwidth of FTA. CTA performances a wide range of pointing and tracking, with tracking accuracy of up to 120 μrad. However, servo bandwidth of FTA is greater than 300 Hz, with dynamic range of 5 mrad and tracking accuracy of 3 μrad. The planetoground laser communication demonstration experiment is successfully completed, with the distance of 17.5 km, the communication rate of 1.5 Gbps, and BER of less than 1E7.