A copyright registration, transaction and protection method of digital content is realized by an intelligent contract. The copyright registration provides a deposit, publicity period, copyright complaint and judgment right confirmation mechanism, and effectively ensures the accuracy of copyright ownership and the convenience of right protection. The copyright transaction is carried out through auction, and a freezing period, deposit, withdrawal and transaction mechanism is provided, so that the cost is lower, the transaction is easier, and the price is more reasonable. An encryption distribution storage mechanism is adopted for copyright owner identity data, user privacy is guaranteed, an account resetting method under a lost private key is provided, and benefits of copyright owners are protected. According to the digital copyright registration, transaction and protection system, through a digital signature and delegation service mechanism, a trust server and an agent are not needed, aclient delegates copyright related transactions to the agent and submits the transactions to a block chain node for execution, the use threshold is reduced, and the user experience is improved.