The utility model provides an efficiency that central vacuum system of tower high efficiency, perpendicular and real empty can places 700 millimeters diameter in real empty can's top, highly reaches the condenser more than 5 meters, and the temperature of gas that can the intraductal circulation of effectual reduction makes the vapor cooling condense into water, dwindles gaseous volume in the vacuum system, the effectual vacuum system that has promoted. The vacuum system of these central authorities has disposed side passageway pump, has constituteed one set of negative pressure drainage system with the last liquid level floating ball switch in the real empty can, lower liquid level floating ball switch, has improved central vacuum system's the vacuum and the stability of negative pressure. The vacuum system of these central authorities has installed U type clearance pipeline, metal rubbish such as the bolt that drops from the mould, nut through U type pipeline can the complete U of falling into type the bottom. Thereby avoid flowing the relevant valve of real empty can bulk damage and side passageway pump, the effectual reliability that promotes central vacuum system.