In view of the dispersion and attenuation properties of the cable line to the traveling wave, the application of the conventional traveling wave method on the cable line is limited. In response to this problem, this paper proposes a protection scheme suitable for cable lines. The scheme extracts the line pole line quantity and performs phase-to-mode conversion, and then obtains the line mode and ground mode traveling wave components to construct an overall protection scheme. Using wavelet analysis complex wavelet Morlet to obtain the phase information in the fault modulus, using the phase difference between the internal and external faults can effectively identify the fault. Simulation based on PSCAD and Matlab verifies the effectiveness of the method. Compared with the traditional traveling wave protection scheme, this protection scheme has stronger ability to withstand over-resistance..