The invention discloses a method for preparing N-hydroxyethylaniline by using an ionic liquid, belonging to the field of organic chemical synthesis. According to the method, N-hydroxyethylaniline is prepared by taking phenylamine and chlorohydrin as starting raw materials and using an ionic liquid which is good in thermal stability, difficult to volatilize and recyclable as a catalyst and a solvent. In the method, no any other poisonous and harmful catalysts are used, and reaction condition is mild, selectivity is good and yield is high. The method disclosed by the invention is an efficient new method for synthetizing N-hydroxyethylaniline.