The invention discloses a decentralization-based mobile hard disk encryption and decryption method. The method comprises the following steps of S1, configuring a unique identification code corresponding to a storage mobile hard disk at a remote server, configuring multiple sets of mobile hard disk permission driver loading programs and a hard disk operation basic driver loading program in the remote server, and configuring a file opening permission corresponding to each set of permission driver loading program; S2, configuring a mobile hard disk trusted device list in the remote server; S3, obtaining mobile hard disk loading information, and sending the mobile hard disk loading information and corresponding device loading information to the remote server; S4, configuring the file opening permission corresponding to a legal user in the mobile hard disk by the remote server; and S5, judging whether a device is in the configured mobile hard disk trusted device list or not according to device information by the remote server.