The utility model discloses a cubical switchboard on -line monitoring device, the hall sensor who is used for gathering the current signal on the separating brake coil loop circuit that sets up respectively at the circuit breaker and combined floodgate coil loop circuit, with the signal conditioning circuit that the hall sensor electricity is connected, signal conditioning circuit passes through analog -digital conversion chip and is connected with the controller, controller control analog -digital conversion chip carries out signal acquisition, analog -digital conversion chip returns data collection to the controller. The utility model discloses a cubical switchboard on -line monitoring device can provide a large amount of continuous exception data, avoids discretization, the pieceization of information, discovers adventitious trouble sign early, discovers equipment trouble early warning characteristic greatly in advance, reduces the trouble and causes the loss.