Abstract: Research the narrow image of watermark security problems.In view of the traditional three-dimensional grid anti-counterfeit watermarking algorithm for normal images taken effect is good,to reduce the image watermarking,anti-counterfeiting watermark invisibility and image of the disadvantages of aggression are weaker.Is suggested to consider an after shrinking anti-counterfeiting watermark algorithm of reduction characteristics.To reduce images,shrinking due to its image characteristics,needs to be 3dmodel transformation for 2-d numerical matrix,and USES the two-dimensional block discrete cosine transform;And then USES the particle swarm optimization algorithm find the optimal anti-counterfeiting watermark embedding positions,to embed the anticounterfeiting watermark best position,finally with anti-counterfeiting watermark is obtained by inverse transformation of three-dimensional network image.Simulation results show that the method of embedded anticounterfeiting watermark not only can resist a variety of different types of attacks,and has good invisibility,anticounterfeiting accuracy increased by 64% than the traditional algorithm,resistance to attack increased by 25%,for image copyright protection provides a strong support,in the work of digital image copyright protection with strong practical application value.