The invention aims to provide an intermittent technology and a device for treatment and recovery of chlorosilane residual liquid and residue thereof, especially a method and a device for recovering hexachlorodisilane with very high value. The invention puts forward an intermittent technical scheme for the circumstance of a small residual liquid treatment amount. The technology mainly involves a primary rectification tower and an intermittent rectification tower. The method and the device provided in the invention are particularly applicable to treatment of the cold hydrogenation slag slurry and rectification residual liquid in polysilicon production, the rectification residual liquid and other dirty residual liquids in a synthesis process, and are also applicable to the rectification residual liquid in a reduction process and the rectification residual liquid in a thermal hydrogenation process or mixed type residual liquids, etc. With the treatment technology disclosed in the invention, hexachlorodisilane with purity above 98% can be recovered.