The invention discloses an anti-break monitoring system of a cable. The anti-break monitoring system of a cable includes a sensor fiber, an interference demodulator, a sample signal memory unit, a signal comparison unit and an alarm unit, wherein the sensor fiber closely abuts against a power cable in parallel, and any one end of the sensor fiber is connected with the interference demodulator; the signal comparison unit is connected with the interference demodulator and the sample signal memory unit; the alarm unit is connected with the signal comparison unit; the sensor fiber is a sensor fiber of a probing detection signal; the interference demodulator is used for demodulate changes of the optical signal phase generated from vibration of the sensor fiber; and a signal comparison unit receives the vibration signal demodulated by the interference demodulator and the vibration sample signal stored in the signal storage unit. The anti-break monitoring system of a cable can alarm timely, and can timely realize damage of external power.