Abstract: The time-domain positioning signal collected by the traditional time-frequency domain reflection method (TFDR) is an input reflection superposition signal. Therefore, when calculating the time-frequency energy distribution of the signal using the Wigner distribution (WVD), cross-term interference occurs due to the coupling between multi-component signals. To address this issue, synchrosqueezing transform (SST) is used to compress and rearrange time-frequency coefficients, achieving high-resolution expression of complex multi-component signals, eliminating cross-term interference, and achieving high spatial resolution in the localization spectrum. Simultaneously analyze the parameters related to the reference signal and propose design principles for reference signals for testing different cable lengths. Firstly, the time-domain positioning signal is obtained by using the TFDR method. Then, SST is used to obtain the compressed and rearranged time-frequency spectrum, obtaining a more accurate time-frequency expression and eliminating cross-term interference. A 10kV cross-linked polyethylene cable simulation model was built for research, and a 500m long XLPE power cable with intermediate joints was selected for experimental verification of the algorithm. And conduct on-site testing and verification on a 32-kilometer submarine cable in a certain location. The simulation and experimental results show that the SST algorithm can effectively eliminate unwanted interference and improve the positioning accuracy of the time-frequency domain reflection method after signal rearrangement.