1. A complex background-oriented optical character recognition method, comprising: capturing image information, to obtain a captured image; acquiring a region of target characters from the captured image based on character characteristics as a target object; extracting character edge information in the target object by using a differential method, to obtain an extracted image; superposing the target object and the extracted image, to obtain a recovery image; performing an inverse and a Gaussian filtering on the recovery image, to obtain a processed image; searching for a location of the target characters in the processed image; and recognizing the target characters.