Method for purifying ethylenediamine

The invention discloses a method for purifying ethylenediamine, comprising the following steps: (1) heating extractant, feeding the extractant in to an extracting tower from the upper part of the extracting tower, gasifying 60.0-92.0% water-bearing ethylenediamine, feeding the ethylenediamine into the lower part of the extracting tower, making the ethylenediamine reversely contact the extractant on the upper part of the extracting tower in the extracting tower, discharging water from the top of the extracting tower and separating the mixture of the ethylenediamine and the extractant at the bottom of the extracting tower, wherein the extractant is diethylene glycol monomethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether or diethylene glycol monobutyl ether; and (2) heating the mixture of the ethylenediamine and the extractant, feeding the mixture of the ethylenediamine and the extractant to the middle part of the extracting tower, rectifying the mixture ofthe ethylenediamine and t