Abstract: A method for backing up and restoring a license is provided, which solves the problem of right proliferation in the prior art caused when an original license is transmitted to a user when a server restores the license. The method includes: backing up, at a server, license information of a first device, and associating the license information with a user identifier, the license information reflecting the current state information of a license when the first device reports the license information the last time; requesting, by a second device, the server to restore the license; and validating, by the server, a user identifier of the second device and the user identifier associated with the license information, and upon determination that the two user identifiers are consistent, generating a license based on the license information backed up, and transmitting the license to the second device. A terminal device, a server, and a license processing system are also provided.