Abstract: Aiming to locate faults automatically in situations of long cables and strong attenuation, a cross-correlation based time-domain-reflectometry（TDR） cable fault location method was presented. Based on the analysis of the transmission characteristics of cables, it was proved that the dispersion is the only effect that decreases the precision of correlation analysis. Bi-polar rectangular wavelet pulses were designed, which have concentrated energy spectra and can be generated with low-cost switches. Simulations and experiments show that the location precision of wavelet-pulse-based TDRs is higher than traditional TDRs and close to Gaussian-envelope-pulse-based TDRs. Besides, wavelet-pulse-based TDRs have strong noise resistance.