Abstract: The openness of 2D barcode coding rule makes regenerating the same content 2D barcode become possible, which further makes the invisible watermarking technology on 2D barcode become necessary. This paper proposes a watermarking algorithm for print-scan process on 2D barcode. The characteristics of QR code and the influence of print-scan process on the DCT coefficient are firstly analyzed. And then, the artificial blur and noise are used in the proposed algorithm to improve the invisibility and grayscale and the DCT coefficients in specified position are intensified. Finally, the intermediate frequency coefficient classification statistical method is used to realize the watermark embedding. The experimental results show that compared with the algorithm without using intensified coefficient, the proposed algorithm in this paper can attain stronger robustness and higher invisibility.