The invention discloses an anti-theft alarm system for a ground lead of a feeder cable. The device comprises a power supply unit, a switching value collecting unit, a logic comparison operating unit,a relay output unit, a sound alarm unit and a wireless emitting unit, wherein the input end of the power supply unit is connected to a CT inductive taking device, the output end of the power supply unit supplies power to the switching value collecting unit, the logical comparison operating unit, the relay output unit, the sound alarm unit and the wireless emitting unit, and the switching value collecting unit transmits the collected data to the logic comparison operating unit, and the logic comparison operating unit controls the relay output unit, the sound alarm unit and the wireless emittingunit. The system disclosed by the invention solves the problem of monitoring of a stolen primary ground lead of a cable line, and healthy and stable operation of the cable is guaranteed.