Abstract: Power cable has many advantages such as high reliability, strong power supply capacity, space saving, environmentally friendly and so on. Therefore the penetrance of power cable in city distribution network is increasing. In the paper the successively tripping fault of one particular distribution network multi-cable line is studied. Aiming to one bus, the fault of 10kV multi-cable lines, grounding current of cable shielding layer, and impact of zero sequence current on correct wiring and neutral point earthing of users sides are studied. The coupling grounding fault is analyzed combining time and space, also the occurrence and development of fault is deduced. Finally, some advices are proposed for better operation and dealing with complicated coupling fault.