A third-party interference monitoring system is provided. The third-party interference monitoring system, according to one embodiment of the present invention, is for detecting third-party interference in advance before a buried pipeline buried underground is damaged by the third-party interference. The third-party interference monitoring system comprises: a sensor unit which is installed on a buried pipeline so as to detect an impact signal which is propagated along the ground or the buried pipeline when heavy equipment strikes the ground; and a control unit which acquires a time domain value of the impact signal by receiving data from the sensor unit, converts the time domain value to a frequency domain value, and then detects the third-party interference on the basis of frequency response characteristics of the impact signal.