The invention relates to a shutter mechanism on a switch cabinet, and also relates to a switch cabinet body and a switch cabinet using the shutter mechanism, so as to solve the problem of inconvenience caused by maintaining the shutter open by an external force when the existing shutter mechanism is in power-off repair. Wherein the shutter mechanism comprises a fixed base, upper and lower crank arms, the upper crank arm and the lower crank arm have an open position which is in a crossed state when the flap is opened, it also has a closing position which is distant from each other when the flapis closed, characterized in that the upper crank arm and the lower crank arm are respectively provided with an upper locking hole and a lower locking hole for locking pin insertion, and the upper locking hole and the lower locking hole have a coincident state in a direction parallel to the rotation axis of the lower crank arm of the upper crank arm box when the upper crank arm and the lower crankarm are in a cross state. The mechanism can maintain the cross state of the upper crank arm and the lower crank arm by inserting the locking pin into the upper locking hole and the lower locking hole, thereby maintaining the shutter in an open state and facilitating operation.