The building intercom system is to install a security door at the door of each unit, and the administrator switchboard of the main control center of the community, the intercom host at the entrance and exit of the building, the electric lock, the door closer and the visual intercom extension at the user's home form a special network. ? So as to realize the intercom between visitors and residents, the residents can remotely open the security door, the visitors of each unit staircase call the residents through the intercom host, and the other party can only enter the building after agreeing, which restricts the entry of illegal personnel. ? At the same time, if there is a robbery or sudden illness at home, you can notify the security personnel through the system and get timely support and treatment. ?