Method for establishing communication connection between local area networks, user side equipment and gateway equipment

The invention provides a method for establishing communication connection between local area networks, user side equipment and gateway equipment. Interaction data between two local area networks is transferred through a transfer server with a public network IP, and after a server of a network server receives a connection request of the user side equipment to the appointed gateway equipment, the server transmits the first encryption and decryption information to realize secure communication between the user side equipment in the first local area network and the equipment in the second local area network where the gateway equipment is located, and remote upgrading of software and remote equipment debugging are facilitated. According to the embodiment of the invention, a communication connection virtual network tunnel is established, a communication service of the virtual local area network is provided for the user side equipment and the equipment in the second local area network, and then remote local equipment