An updating method including: acquiring, by an active update node, update information from a server; and acquiring or receiving, by a passive update node, the update information from the active update node through a local network. By using the update method and system, end node and electronic device provided in the present disclosure, an active update node of a plurality of end nodes in the same local network acquires update information from a server, and a passive update node acquires the update information from the active update node, thereby reducing the number of end nodes acquiring the update information from the server, and reducing the burden of the cloud.