Distribution cables gradually deteriorate under several kinds of stresses

which may result in its breakdown and affect the safety and reliability of power system. In order to diagnose the cable deterioration status

dielectric response

the time domain method represented by polarization/depolarization current（PDC） and the frequency domain method represented by frequency domain spectroscopy（FDS） were applied to determine cable insulation status based on the characteristic parameters. According to existing results

the PDC method which is widely used and mature is supposed to be applied in power system maintenance. However

the PDC method is easily interfered by outside electromagnetic environment during on-site tests. The FDS method has the advantages of anti-interference and information richness; However

the FDS method is not able to diagnose long cable in high frequency due to the conflict between excessive power cable capacitance and limited capacity of measuring equipment. As a result

to increase the measurement efficiency

further related research should start from the dielectric response theory and combine with the advantages of time/frequency domain to improve test frequency band by studying the matching and conversion method.