The invention discloses a vision auxiliary device and method for automatic landing of an unmanned aerial vehicle, and relates to the field of unmanned aerial vehicles. The problems that according to an existing vision auxiliary device which acquires and recognizes runways and the horizon through an airborne photographing device so as to sense the landing posture of the unmanned aerial vehicle, due to the lack of a multi-scale analysis mechanism, the landing requirement cannot be easily met, the posture and position calibration effect is poor, and deep prediction of the movement behavior of the unmanned aerial vehicle lacks are solved. The vision auxiliary device comprises a two-shaft rotary table, a rotary table motor, a power module, a single-view fixed-focus camera, a vision auxiliary information processing module and an information storage module. The vision auxiliary information processing module comprises a landing track re-planning module, a data comparator, an information filter, a computer vision processor based on image control, a computer vision processor based on position control, a first feedback correction device, a second feedback correction device, an information fusion parameter extractor and an RS485 communication interface. The vision auxiliary device is simple in structure, low in power consumption, high in efficiency and good in compatibility.