In recent years, the use of unmanned aerial vehicle(UAV) for power transmission line detection is a hot technology, and it can detect the transmission line and discriminate the failure without power off. According to the features of power transmission line equipments, a method of equipments recognition based on image processing and pattern recognition was put forward. It preprocessed the aerial images by median filtering, dilating and eroding. Then, wavelet eigenvalues of preprocessed images were calculated. Finally, the objects, such as insulator, vibration damper and transmission tower, were classified and recognized by affinity propagation (AP) clustering algorithm. The results of experiments show that this method can recognize the insulator, vibration damper and transmission tower, and it has better robustness, accuracy and validity.