With the growth of bridge service life, the bridge structures gradually enter the stage of high maintenance and high risk under the comprehensive action of internal factors such as aging and degradation of structural materials and external factors such as vehicle load, typhoon, earthquake and flood. The traditional bridge inspection is mainly taken by the inspectors to directly identify and record the bridge diseases with pen and paper, which has the characteristics of strong repeatability, interrupted traffic and working at heights. With the rapid development of Internet of Things, close-range photogrammetry, machine vision and other technologies, it is gradually possible to replace the artificial vision with UAV-assisted vision technology to complete the bridge inspection. An automatic inspection method for bridge apparent diseases is put forward based on UAV, and the effectiveness of the method is verified through the engineering practices.