A barcode detection method includes acquiring an image by a camera, acquiring a horizontal gradient and a vertical gradient of each pixel of the image within a region, generating a gradient phase and gradient magnitude of each pixel according to the horizontal gradient and the vertical gradient, performing a binarization process to the gradient magnitude of each pixel of the image within the region for generating a binarized image, vertically and horizontally sampling the binarized image for generating the gray level flip count in a vertical direction and a horizontal direction, locating an image region of a barcode according to the gray level flip count in the vertical direction and the horizontal direction, acquiring a plurality of gradient phases of all pixels within the image region for generating a gradient phase distribution, and generating a barcode format detection result according to the gradient phase distribution.