The utility model relates to a device for continuously producing chlorinated poly vinyl chloride (PVC) through a low-temperature plasma circulating bed, which comprises a poly vinyl chloride particle material cabin, a chlorinated poly vinyl chloride material cabin, two fluidized bed reactors in parallel arrangement, two riser reactors in parallel arrangement, a downer reactor, a tail gas purification device and two circulation fans, wherein the two circulation fans are respectively used for conveying riser conveying gas and raw materials. The device utilizes the characteristic that the low-temperature plasmas can be used for simultaneously activating chlorine gas and PVC raw material particles, the fast PVC chlorination is realized in a circulating fluidized bed, simultaneously, the alternate operation mode of two groups of fluidized bed reactors is adopted, and the continuous production is realized. Therefore, on one hand, the problems of production efficiency reduction and the like caused by material discharging because of reactor machine halt is avoided; and on the other hand, the machine halt restarting of the fans, tail gas treatment devices and the like can be avoided, energy source consumption is saved, and the service life of equipment is prolonged.