The invention discloses an interlocking device of a valve and a grounding switch. The device comprises a cabinet body, an interlocking plate, a transmission mechanism, a bent plate and a grounding switch operating shaft, wherein a locking plate is arranged on the grounding switch operating shaft, the transmission mechanism comprises a transmission shaft, a baffle plate and a transmission element are arranged on the transmission shaft, one end of the interlocking plate is connected with the transmission element, a locking tongue is arranged at the other end of the interlocking plate, and a lock catch and a through hole are arranged on the bent plate; when the valve is in a closed state, the interlocking plate prevents the bent plate from downwards moving, and the bent plate blocks a grounding switch operating hole; and when the valve is in an open state, the interlocking plate is rotated under the driving of the transmission shaft to remove the limitation on the bent plate, the bent plate downwards moves to make the grounding switch operating hole exposed, and the locking plate is used for limiting the baffle plate. In the interlocking device disclosed by the invention, the operation of a grounding knife switch cannot be fulfilled when an isolation switch is in a switch-on state; and the locking plate on the grounding switch operating shaft is used for locking the transmission shaft after the grounding knife switch is switched on, and thus, the operation of the isolation switch cannot be fulfilled after the grounding knife switch is switched on.