The invention provides a software upgrade method, device and system. The method comprises the following steps: sending a software upgrade request to an upgrade server; acquiring response information corresponding to the software upgrade request returned by the upgrade server, wherein the response information is used for indicating address information of a first terminal which has acquired the upgrade data; acquiring the upgrade data acquired by the first terminal according to the address information, and upgrading the software according to the upgrade data. By use of the technical scheme provided by the invention, the problems that the software upgrade of the set top box system occupies long bandwidth time and is long in upgrade period in the prior art are solved, and then the effect of fast accomplishing the upgrade process on the set top box terminal is achieved.