The utility model relates to a signal monitoring system that discharges of cubical switchboard, including centralized control unit, monitoring host and installing support, be connected with voltage sensor, ultrasonic sensor, temperature and humidity sensor, noise sensor on the centralized control unit, monitoring host links to each other with the centralized control unit, the last remote interaction terminal that is connected with of monitoring host, the installing support can be dismantled with the cubical switchboard of being monitored and be connected, the utility model discloses an advantage: realize voltage sensor through the centralized control unit, ultrasonic sensor, temperature and humidity sensor and noise sensor generate real -time collection the in succession of signal, and receive the data that the centralized control unit was uploaded through the control subassembly, can put the signal to the office of cubical switchboard tentatively fixes a position and judges with the type of discharging, and play a game in a short time and put the signal and carry out on -line monitoring, in time feedback signal changes, the office of prevention in the cubical switchboard puts the defect and further aggravates the sudden trouble of equipment that probably leads to, guarantee the safe operation of cubical switchboard and low pressure looped netowrk cabinet, effective enhancing power supply reliability.