The invention provides a front and back vehicle license plate recognition method based on video detection. A first vehicle license plate recognition device which is perpendicularly installed on the ground and provided with a wide-angel lens with 90 degrees or above is used for recognizing front and back vehicle license plates. The method comprises the following steps of target detection, wherein a motion target passing through a preset monitoring area is captured, and a target motor vehicle is screened out; tracking and snapshotting, wherein the motion track of the detected vehicle inside the monitoring area is tracked, and pictures of the front and back license plates of the same target vehicle are snapshot; vehicle license plate recognition, wherein the snapshot pictures of the front and back vehicle license plates are processed, and front and back vehicle license plate recognition results are obtained; related comparison, wherein the front and back vehicle license plate recognition results output by the step of vehicle license plate recognition are compared, and a comparison result is output; result output, wherein according to the comparison result, the vehicle with different front and back vehicle license plates is screened out, and vehicle license plate information of a suspected fake-licensed vehicle with different front and back vehicle license plates is output.