Method and system for sharing WIFI, household gateway, and local area network gateway

The invention discloses a method for sharing WIFI. A household gateway receives a message sent by wireless user equipment; under the condition that the user equipment is first user equipment, the message is encapsulated to be a first generic routing encapsulation (GRE) message; the first GRE message is sent to a local area network gateway (WLAN Gateway) through a GRE tunnel; when the user equipment is second user equipment, the message, after being accessed to a server through broadband, is directly sent to Internet. The invention further discloses a system for sharing WIFI, a household gateway and a wireless local network gateway. According to the invention, a first user and a second user are enabled to share the WIFI together, first user service and second user service are separate, users can be accessed to networks more conveniently, securely and rapidly, the investment cost of operation enterprises is decreased, and the utilization rate of resources is improved.