The present invention belongs to the unmanned aerial vehicle technical field and relates to a large-visual field bionic fish eye-based small unmanned aerial rotorcraft moving target low-altitude tracking method. The method includes the following steps of: (1) calibrating a fisheye lens: the fisheye lens is calibrated with a monocular lens calibration method, so that the internal parameter and distortion coefficient of the lens are obtained so as to be applied to the distortion correction of an image acquired by the fisheye lens; and (2) target visual tracking: a fish-eye lens target surrounding small area distortion corrected image is adopted to carry out target feature generation and search matching tracking. According to the method, the monocular fisheye lens is adopted to carry out visual tracking; algorithm strategies used in the method can cleverly reduce computational complexity; the limitations of the use of the fisheye lens can be decreased; the advantage of the large visual field of the fisheye lens is fully utilized; a camera pan-tilt holder is omitted; the complexity of an unmanned aerial vehicle control algorithm is decreased; and an excellent tracking effect is achieved.