Detecting abnormal discharge from transmission lines is crucial to the safe operation of power grids. To detect and locate the abnormal discharge of power equipment such as transmission lines and insulators， first， a corona discharge ultraviolet detection model is established based on the traversing tiny unit method； the ultraviolet transmission characteristics in the atmospheric channel are studied； and the relationship between the path loss and position of the detection equipment under different corona discharge directions is obtained. Second， by considering the relative position relationship between the detection device and discharge point， the corona discharge point location method is obtained based on the moving speed of the detection device and steering angle when receiving the maximum ultraviolet power. In addition， according to the detection distance and received ultraviolet power， a method for retrieving the simulated discharge power is obtained to determine whether there is an abnormal discharge. At last， an experimental platform is built to verify the algorithm outdoors. The experimental results demonstrate that， when the inspection distances are 15， 20， 25， and 30 m， respectively， the positioning error of the algorithm for the discharge point is <8%， and the error of retrieving the simulated discharge power is <10%， which proves the effectiveness of the algorithm.