Closed powder conveying device

The utility model relates to a closed powder conveying device, and belongs to the technical field of powder material conveying equipment. The closed powder conveying device comprises a negative pressure conveying module and a positive pressure conveying module, the negative pressure conveying module comprises a material collecting bin, an unpacking device, a material sending tank and a negative pressure generator, and material level limiting sensors are installed on the material collecting bin and the material sending tank; the positive pressure conveying module comprises a material storage tank composed of a first material storage tank and a second material storage tank, a nitrogen storage tank and a material suction metering tank, and material level limiting sensors are installed on the material storage tank and the material suction metering tank. The closed powder conveying device is a positive and negative pressure combined type closed powder conveying device, has the characteristics of reasonable structu