在建立紫外自由光通信系统通信传输距离方程的基础上，针对紫外大气传输衰减、光学系统性能、探测器性能、误码率和信噪比等因素对通信传输距离的影响进行了具体分析，并对系统的通信传输距离进行了仿真计算。结果表明，在目前的技术水平下，系统的理论通信传输距离一般不超过 4 km，这与目前实际系统的通信传输距离符合较好。这对近地层紫外自由光通信系统的设计和性能评价具有一定的理论指导作用和现实意义。

On the basis of the transmission equation of the ultraviolet free optical system, analyze in detail the impact of air transport attenuation, the performance of optical system, the performance of detector, bit error rate and signal to noise ratio on transmission distance, and calculate the transmission distance of system. The result shows that in the present level of skill, the theory transmission distance is generally not more than 4 kilometers, which match better with the present transmission distance of system. The research will shed light on the theory and practice of designing and judging near ground ultraviolet free optical communication system.