The invention discloses a power-failure cable stealing-preventing monitoring method based on a traveling wave method. The power-failure cable stealing-preventing monitoring method includes the specific steps of (1) inputting a low-voltage signal with the fixed frequency and the fixed amplitude; (2) collecting a reflection signal; (3) judging whether a cable is stolen, proceeding to the step (4) if the cable is stolen, and proceeding to the step (1) if the cable is not stolen; (4) calculating the accurate position of the stolen cable. By means of the power-failure measurement method, cable stealing monitoring can be achieved only by emitting the low-voltage signal with the fixed frequency and the fixed amplitude to the power-failure cable and processing received information, and the power-failure cable stealing-preventing monitoring method is low in cost, easy to operate, high in testing accuracy and good in stability, and has the remarkable advantages in steeling preventing monitoring on the power-failure cable.