Discrete wavelet transform is not only better suited to the characteristics of human visual system, but also better adapted to JPEG2000 and MPEG4 compression standards. The carrier image obtained by embedding watermarking information into the carrier image by wavelet transform has good visual effect for human eyes, and the watermarking information in the carrier image has strong resistance, so the research of the digital watermarking technology based on wavelet is of great significance to current situation. Using a digital watermarking technology based on wavelet transform, the low-frequency subgraph is divided into blocks and its wavelet coefficients are quantified. The Arnold scrambling algorithm is used to embed the watermarking into the target image and extract the watermarking completely from the target image. And the robustness of the Arnold scrambling algorithm in the wavelet transform is demonstrated by common watermarking attacking on the watermarking information.