In order to solve the problems that copyright owners maliciously frame purchasers up and purchasers know their own watermarks so remove them easily during the digital content copyright protection and tracking processes， a digital content copyright protection and fair tracking scheme based on blockchain was proposed. Firstly， Paillier homomorphic encryption algorithm and key distribution smart contract were used to change the purchaser’s watermark in ciphertext state， and the watermark was embedded in the encrypted digital content. Secondly， the key distribution smart contract and arbitration smart contract were called by the verification node in blockchain， which solved the single point of failure problem in the traditional copyright protection solutions. Finally， experiments were conducted to verify the performance of the proposed scheme. The results show that when the digital content size is 1 024×1 024， compared with the blockchain-enabled accountability mechanism against information leakage in vertical industry services， the proposed scheme has the total execution time of encryption and watermark embedding reduced by 94.92%， and the total decryption execution time reduced by 79.72%. It can be seen that the proposed scheme has low total time and operating costs with good efficiency， and can be widely used in the field of digital content copyright protection.