With the rapid development of the audio-video industry, the copyright protection of audio-video productions has attracted more and more attentions. The centralized management of the traditional digital copyright system leads to the disadvantages of easy disclosure and tampering of copyright data, which becomes a difficult problem of audio-video copyright protection. How to use technologies to determine the copyright in the case of infringement and copyright disputes becomes the key problem. To solve this problem, an alliance audio-video copyright blockchain system (VC Chain) based on the improved PBFT consensus algorithm is proposed. The system prevents data leakage or malicious tampering, and provides a more reliable process of digital copyright confirmation and tracing by cryptography technology, which improves the security of audio-video digital copyright. The experimental results show that the new consensus algorithm optimizes the system in terms of consensus speed and data communication times. Finally, some problems of digital copyright management are pointed out and their corresponding solutions are given.