The invention discloses a method for preparing N-cyanoethyl-N-ethoxylaniline by using an ionic liquid, belonging to the field of organic chemical synthesis. According to the method, aniline, chloroethanol and acrylonitrile used as raw materials are subjected to a one-pot process by using a high-heat-stability low-volatility recyclable ionic liquid as a catalyst and solvent to prepare the N-cyanoethyl-N-ethoxylaniline. The method does not use any toxic or harmful catalyst, is simple to operate, has the advantages of simple after-treatment, mild reaction conditions, favorable selectivity and high yield, and is a green novel method for efficiently synthesizing N-cyanoethyl-N-ethoxylaniline.