An ultraviolet light transmission experimental system is designed with a 275nm light emitting diode as the light source and photodiode as the detector. Firstly, the transmission characteristics of the system under two transmission modes, line-of-sight and non-line-of-sight, at different distances are tested. Then the transmission characteristics under different light source elevation angles and detector elevation angles are tested. Finally, the experimental results with the theoretical results are compared. The results show that in the non-line-of-sight mode, the received power is inversely proportional to the elevation angle of the light source, and the farther the distance, the smaller the effect of the elevation angle of the light source on the transmission characteristics of the system. The elevation angle of the detector at 30°~60° has little effect on the transmission characteristics of the system. The results of this research provide a certain reference for the design of ultraviolet communication system.