Laser communication, with its wide bandwidth, good confidentiality and no electromagnetic spectrum constraints, has become an effective means to construct high-speed communication in the air, space, earth and sea integrated communication networks. Compared with space-based, the air-based laser communication system, which is carried on balloon, airship, unmanned aerial vehicle aircraft and other platforms, has become the first choice for high security military network, disaster relief emergency network and commercial low-cost network due to its good flexibility, low cost and good maintainability. The latest research progress and main parameters of air-based laser communication system in USA, Germany, France and China are introduced in detail. The trend of one-to-many, lighter weight, wider bandwidth and the challenges of complex atmospheric channel and serious background noise are summarized, and key technical method, such as high dynamic capturing and tracking, high density integration and high sensitivity reception are proposed, which can provide references for air-based laser communication research.