The invention discloses an electric transmission line spacer identification method for unmanned aerial vehicle inspection. A digital image processing algorithm is used for automatically identifying and positioning electric transmission line spacers. According to the method, the relation and the shape of the spacers and a lead wire are used for positioning the spacers. The digital image processing algorithm can be used for effectively positioning the spacers in an electric transmission line, and very important practical significance is achieved for operation and maintenance of power equipment. The electric transmission line spacer identification method for the unmanned aerial vehicle inspection is suitable for outdoor application, and is good in image processing effect under complicated backgrounds.