复用技术能够利用现有的硬件设备和成熟技术，成倍地提高系统容量，已经成为高速空间光通信的重要技术手段。文章从提高信息传输速率的角度出发，研究了偏振复用、波分复用、时分复用、光MIMO以及正交频分复用五种复用技术在空间光通信应用的基本原理，并介绍了最新研究动态。对比分析了空间光通信中五种复用技术的优缺点，结果表明正交频分复用和光MIMO技术是实现空间光通信海量信息传输的有效途径之一，具有很大的发展潜力。

The division multiplexing technology, which can improve the capacity of the system by using the present instruments and mature technologies, has become an important technical method for highspeed space optical communication. From the viewpoint of increasing the speed of transmitting information, the recent progresses and basic principles of five kinds of division multiplexing technology are introduced, including polarization division multiplexing, wavelength division multiplexing, time division multiplexing, optical MIMO and orthogonal frequency division multiplexing. The advantages and disadvantages of each division multiplexing technology are analyzed. The analytical results indicate that the orthogonal frequency division multiplexing and optical MIMO is one of the effective methods for realizing the transmission of massive information.