The utility model discloses an electric pencil sharpener, including a face shell, a garbage cover, a gear box, a battery case and a knife rest; an output shaft of the gear box is connected with the knife rest; the garbage cover and the face shell are locked; the electric pencil sharpener also includes an adjusting block which is connected on the face shell through an elastic piece; and the adjusting block is located on an outer side of the knife rest. In the utility model, the adjusting block is driven by an external force to move as the adjusting block and the face shell are connected through the elastic piece; the knife rest is detached when a bottom of the adjusting block is higher than a highest position of the knife rest only by pushing the adjusting block upwards; the knife rest is assembled by using the above-mentioned operating method; and after assembly, the adjusting block returns to a shielding state under the action of the elastic piece after releasing the external force. The knife rest and a blade are conveniently to be replaced through installation of an adjusting block on the face shell; and compared with a conventional electric pencil sharpener, it is convenient and safe to replace the knife rest and the blade.