Disclosed herein is a cable fault diagnosis system and method, wherein when an application signal and a reflected signal overlap each other due to the proximity of a fault location to an application location or when the intensity of the reflected signal is weak and thus falls outside of a prescribed fault diagnosis range due to remoteness of the fault location from the application location, a correction location, at which a correlation function value has a global maximum, is derived on the basis of a prescribed correlation function for an application signal applied to a cable to be inspected and an acquired reflected signal, a correction signal, which is a reflected signal from which the application signal is removed at the derived correction location, is calculated, the distance between the correction location and the acquisition location is derived on the basis of a time delay, which is calculated on the basis of the calculated correction signal and the reflected signal at the acquisition location, and a propagation velocity, and therefore, even when the application signal and the reflected signal overlap due to the proximity of the fault location to the application location, the fault type and the fault location of the cable to be inspected may be accurately detected, and even when the intensity of the reflected signal is weak due to remoteness of the fault location from the application location or due to a minute fault level, accuracy and reliability of the fault type determination and the fault location detection for the cable to be inspected may be improved.