The invention relates to the field of high-voltage electrical switches, in particular to a fracture structure, an arc extinguishing chamber and an on-off device. The fracture structure comprises two static contacts arranged at an interval and a movable contact matched with the static contacts, wherein the movable contact is a double-end contact capable of connecting and disconnecting with the two static contacts synchronously through movement. The arc extinguishing chamber and the on-off device adopt the fracture structure respectively. Under the condition of equal voltage grade, excellent on-off capability is guaranteed, auxiliary arc extinguishing mechanisms such as a nozzle in the prior art can be abandoned, and the requirement on the operating power for an operating mechanism is correspondingly reduced, so that the cost input of the arc extinguishing chamber and the operating mechanism can be reduced; meanwhile, the structure is simple and the weight is light, so the brake separating and closing speed of the mechanism can be greatly increased, the on-off performance of the on-off device is further optimized, and the on-off device is economic and practical.