The invention discloses a method for generating and authenticating digital image tampered content recoverable variable capacity watermarks, which comprises the following steps of: dividing 2*2 image blocks into smooth image blocks and non-smooth image blocks, extracting 6bit characteristics from the smooth image blocks, extracting 12bit characteristics from the non-smooth image blocks, encrypting the characteristics of the image blocks to generate image block recovery watermarks, randomly embedding the image block recovery watermarks into other image blocks, and judging the authenticity of the image blocks by comparing the consistency of the characteristics of the image blocks and combining block neighborhood characteristics. For the judged tampered image blocks, different tampering recovery operations are executed in two steps according to whether the corresponding recovery watermarks of the image blocks are tampered to improve the tampering recovery quality. The variable capacity recovery watermarks are generated according to the personal characteristics of the image blocks, and the recovery watermarks are simultaneously used for tampering positioning and tampering recovery, so the watermark embedding capacity is reduced when enough image characteristics are ensured, and watermark-containing image quality and tampering recovery quality are considered; and meanwhile, the security is improved, and known forging attacks such as joint attack, mean attack and the like can be resisted.