Vacuum feeder is a kind of dust-free closed conveying equipment that conveys granular and powder materials by means of vacuum suction. The air pressure difference between vacuum and environmental space is used to form air flow in the pipeline and drive powder materials to move. The vacuum feeder is composed of vacuum pump (oil-free and water-free), membrane filter bag filter, compressed air blowback device, pneumatic discharge gate, vacuum hopper, delivery hose and other components. The vacuum feeder has the following characteristics: 1. The whole machine is powered by a whirlpool air pump, which is oil-free, water-free and maintenance-free. 2. The entire process is completed in a sealed condition, eliminating dust pollution. 3. The silo is connected by a quick-opening clamp, which is convenient and quick to disassemble and clean. 4. Low energy consumption, low noise and convenient control. 5. The special S-shaped flange is used between the silo and the silo to more effectively prevent dust from overflowing.