Abstract: In order to improve the recognition accuracy of insulators in UAV inspection and effectively reduce the influence of the background texture and illumination, a new insulator recognition method is proposed, which integrates the shape, color and texture of insulators. Aimed at the off-chip defects of glass insulators, a defect-detecting method is presented, which can sense the distance between gravity centers of insulator chips, and has an recognition accuracy of insulators higher than 90%. Based on testing with numerous UVA inspection images of transmission lines, it is proved that the proposed method can effectively recognize the insulators under various complicated background conditions, and detect the off-chip defects of glass insulators.