This paper presents a digital image tamper detection and recovery algorithm, which uses the dither and chaos technology. Certification of generated image and the repair information gained by low frequency sub-diagram and dither technology after wavelet transform can effectively reduce the amount of data. At the same time, the watermark is embedded in high frequency sub-diagram, so as to make the watermark invisible. Chaos technology is used to complete watermark embedding and encryption; and combined with the Chinese remainder theorem, the impact on the image quality can further be reduced. Experimental results show that the algorithm's watermark has high invisibility and robustness, and also can repair tampered images. So it has a high practical significance in the image authentication and recovery.