Method and system for discovering devices among households

The invention provides a method and system for discovering devices among households. The method includes: a public network register server is built, registering of household digital media controller (DMC) devices on the register server is finished through an expanded digital living network alliance (DLNA) protocol, and register information of the household DMC devices is reserved in the register server; a first DMC device obtains an online DMC device list of a household at the opposite end from the register server, and second DMC device information in a retrieve list is requested to the register server according to the list; and the second DMC device of the household at the opposite end obtains response of a digital media server (DMS) or a data media renderer (DMR) device in a local household according to retrieving request forwarded by the register server, and the response is returned to the register server. The expanded DLNA protocol defines online/offline notification messages of the DMC devices, DMC device description files and DMC service description files. The method and system achieves device discovery among one-to-many mode households.