The invention provides a rectification tail gas recovery system. The rectification tail gas recovery system comprises a chlorosilane gas carrying phosphorus and boron impurities, the recovery system comprises a comproportionation tower and an impurity adsorption device, rectification tail gas entering the lower feeding opening of the comproportionation tower is leached by a silicon tetrachloride material entering the upper feeding opening of the comproportionation tower and undergoes a comproportionation reaction in the comproportionation tower, trichlorosilane generated by the reaction and phosphorus and boron impurities carried by the trichlorosilane are output from the gas phase outlet of the comproportionation tower as preliminarily purified gas, residual substances in the rectification tail gas and the unreacted silicon tetrachloride material are discharged from the liquid outlet of the comproportionation tower, and the impurity adsorption device is used for carrying out adsorption treatment on the preliminarily purified gas to remove the phosphorus and boron impurities. The recovery system well recovers chlorosilane in the rectification tail gas, thereby saving the production cost.