Abstract: External substances such as water and air will invade the cable main insulation and threat the safe operation of cable when sheath of cable was damaged.The principle and method of fault location of cable sheath using DC bridge method, voltage comparison method, step-by-step voltage method, audio method and acousticmagnetic synchronization method were introduced.Then, the principle and application of on-line monitoring and fault location of sheath based on sheath current were introduced.Finally, the fault location and monitoring technology of power cable sheath were summarized, and the future development trend was prospected (19 references cited).