Aiming at the discharge problem of transmission facilities in UAV patrol line, the ultraviolet discharge detection system is designed by adopting the ultraviolet discharge detection link model and using photomultiplier. Ultraviolet discharge detection system is used for discharge detection experiment. The experimental results are as follows, the detected signal of the system is highly coincident with the discharge signal, and the intensity of the detected signal of the system is linearly correlated with the intensity of the discharge signal. The relative error between the peak value of the detected signal and the average value of the detected signal is less than 3%, that is, the strength of the detected signal is related to the detected distance and has nothing to do with the detected position. The theoretical value calculated by the model under different detection distances is consistent with the actual detection value, and the maximum relative error is 15. 7%, which verifies the correctness of the model. The results of this paper have some guiding significance for UV discharge detection of UAV in line patrol. Keywords:UAV patrol; UV disch