Pre-pumping negative pressure type powder bagging device

The utility model discloses a pre-pumping negative pressure type powder bagging device. The powder bagging device comprises a transition hopper, a secondary material door, a negative pressure materialbarrel, a closed powder bag clamping device and a bagging gripper, the lower end of the transition hopper is connected with a secondary material door; the secondary material door is provided with a material storage barrel; a material stopping overhead door is arranged below the material storage barrel; the material stopping overhead door is driven by an overhead door cylinder; when the material stopping overhead door is closed, the powder is stored in the material storage barrel and the transition hopper; the lower end of the secondary charging door is connected with a negative pressure charging barrel; wherein the side wall of the negative-pressure charging barrel is communicated with an exhaust pipe, a valve plate is arranged at an inlet of the exhaust pipe and connected with a cylinderrod of a valve plate cyli