This paper proposes an image copyright authentication model that combines blockchain technology, digital watermarking, IPFS(InterPlanetary File System) and perceptual hash function , aiming to solve the secure storage problem of watermark images in digital image copyright authentication. This paper designs a spatial domain watermarking algorithm to implement watermark embedding and detection, and verifies its imperceptibility and correctness through experiments. This paper also uses the content addressing feature of IPFS and perceptual hash function to obtain a unique identifier, and records it on the blockchain to achieve secure storage and distribution of watermark images, and adopts image encryp-tion technology to make them visible but unreadable to unauthorized visitors. The innovation of this paper lies in proposing a digital image copyright authen-tication model that combines multiple technologies, which can effectively protect watermark images from tampering, leakage and infringement.