The invention provides a number plate recognition method and a system thereof. In the number plate recognition method, each driveway on the traffic flow section is provided with number plate recognition video acquisition points to form number plate acquisition view fields on each driveway and number plate acquisition overlapping view fields between adjacent driveways; when a recognized number plate enters the number plate acquisition overlapping view fields, the two number plate recognition video acquisition points of the adjacent driveways acquire partial number plate data of the recognized number plates respectively and generate the recognition results of the partial number plates; the recognition results of the two partial number plates are combined to generate the integral number plate recognition results of the recognized number plates. By adopting the technical proposal, the number plates of all of the vehicles passing on the traffic flow section can be recognized; the overlapping area of the view fields is set to be the size of a number plate characters to ensure that the number plate width accounts for a large proportion of the width of the view field, and effectively ensure high number plate identification rate. In addition, one vehicle is not recognized twice at the same time.