The HVB10 cable fault comprehensive testing system is an intelligent device that solves the fault of the outer protective layer of single core cables. It has four major functions: external sheath withstand voltage test, external sheath fault pre positioning, external sheath fault precise positioning, and arc burning. Through its working principle, the pre positioning function of cable main insulation faults can also be achieved. The equipment system adopts the bipolar voltage drop method (voltage comparison method) for fault pre positioning. Compared with the traditional Wheatstone bridge principle, the pre positioning accuracy is no longer affected by the cross-section and length of the short circuit, nor is it affected by on-site environmental interference.