The present utility model relates to a graphite furnace locking device, comprising: a stationary part which is provided with a locking unit, a movable part which is arranged along a first direction facing the stationary part, the movable part being provided with a latch bolt unit; wherein, the movable part may move towards the stationary part along the first direction until the latch bolt unit and the locking unit are connected and then the locking device is in a locked state; the latch bolt unit provides a first elastic force for the movable part towards the direction of the stationary part; the locking unit is used to disconnect from the latch bolt unit, and then the locking device is in an unlocked state; the latch bolt unit provides a second elastic force for the movable part in a direction away from the stationary part, and the movable part can move away from the stationary part in the first direction under the action of the second elastic force to its initial position. For the locking device of the present utility model, when it is under an unlocked state, the movable part is automatically sprung away to prevent the operator from being injured by scalding.