An improved overvoltage automatic prevention apparatus having individual fault displays and permanent ground functions capable of rapidly and safely protecting load parts of the system from overvoltage caused by a thunderbolt or surge and protecting the communication system by providing automatically operable permanent ground and individual fault display functions when a series of overvoltage is applied thereto, so that easier fault checks, system management, and maintenance is possible, which includes a gas tube connected to subscriber lines and both sides of the electrode surfaces having grooves and having a ground electrode connected to the ground; melting insulation materials inserted into the grooves and defining openings formed at recesses; a permanent ground-side spring connection bar inserted into the openings of the melting insulation materials and receiving a ground electrode of the gas tube and having protruded contact points formed on the inner sides of both connection plates; and a fault display lamp-side spring connection bar connected to an individual fault display lamp and having protruded contact points formed on the inner side of both connection plates and inserted into the other openings of the melting insulation material.