This paper takes 2D character barcode as the research object, makes the recognition problems of 2D character barcode. Because of 2D barcode image having the image blurring problems, This paper enhances image with piecewise linear grey level transformation,and uses improved 2D OTSU method to compute the interval boundary points according to the gray level distribution. The ButterWorth band stop filter is made to deal with the stripe nose appeared in the 2D barcode image. At last use the round-degree method to locate 2D barcode region. Experiments show that, this approach has a good performance on solving the image blurring and noise problems, and it could locate the 2D barcode region quickly and effectively.