The invention discloses an online monitoring method of a switch cabinet 
lightning arrester, a double indirect 
electricity testing method of equipment at the wire outgoing side of a high-
voltage switch cabinet, and a device for realizing the method. In the method and a matched device thereof, a 
voltage signal and a current 
signal are simultaneously taken as 
signal monitoring input signals of the switch cabinet 
lightning arrester, the input signal is subjected to digitalized 
processing so as to display a specific value of a primary 
voltage of the equipment at the wire outgoing side in real time, to be capable of collecting the action times of the 
lightning arrester in a switch cabinet, the accurate time of each action, the leakage full current and resistance current of each phase of the 
lightning arrester, and automatically recording the values of the full current and resistance current in a set time. The device is provided with three current indicating lamps which are directly connected with a three-phase 
lightning arrester. The current indicating lamps can be turned on by the leakage current of the 
lightning arrester directly so as to achieve the purpose of indicating 
electricity. The leakage current indicating lamps of the lightning arrester and line primary voltage form double indirect 
electricity testing so as to reach the standard of switch cabinet indirect electricity testing.