The invention relates to a portable operation tool for grounding in a switching operation process of a substation, in particular to a novel grounding car for a 10kV bus PT cabinet. The novel grounding cable is structurally characterized by comprising a fixed execution component, a car frame component, a sliding component and a plurality of grounding moving contacts, wherein the fixed execution component provides screw driving; the car frame component drives the sliding component to execute an operate; meanwhile, the sliding component can also slide oppositely to the car frame component; the sliding component is divided into an upper layer and a lower layer; an upper sliding component is arranged at the upper layer for correspondingly operating a valve on a busbar side; and a lower sliding component is arranged at the lower layer for correspondingly operating the valve on a PT side. One of the busbar side and the PT side can be flexibly selected for working during operation; and the busbar side and the PT side can also be simultaneously selected for working, so that distant and selective grounding operation is achieved; the states of other equipment are effectively prevented from being changed; the novel grounding car is simple in overall structure and easy to operate; the working potential safety hazard is eliminated; the working security and reliability are ensured; and the visual electrical inspection operation can also be provided.