The present invention relates to a method for preparing a chimeric carbohydrate converting enzyme library, the chimeric carbohydrate converting enzyme library prepared through the method and the carbohydrate converting enzyme prepared through the library, wherein the method comprises identifying a conserved sequence of a carbohydrate converting enzyme and recombining the conserved sequence. By using the smart carbohydrate converting enzyme library according to the present invention, the effect can be realized in that a carbohydrate converting enzyme can be obtained in which the activity and function of the enzyme is not lost at an efficiency of 40% or more, unlike a typical library, and a carbohydrate converting enzyme having various physical and biochemical properties is obtainable. Therefore, an enzyme suitable for various conditions can be selected and used.