The invention provides a rubber earphone hook cutting device which comprises a base. The base is provided with a motor. A rotary shaft of the motor is sequentially provided with a driving friction wheel and a circular blade in the direction away from a motor body, wherein the driving friction wheel and the circular blade are coaxial with the rotary shaft. The base is provided with a slide block capable of sliding in a reciprocating mode in the direction perpendicular to the rotary shaft and rotatably provided with an inserting shaft in a penetrating mode, wherein the inserting shaft is parallel to the rotary shaft. The front end of the inserting shaft can be fixedly inserted into the tail end of a rubber earphone hook, and the tail end of the inserting shaft is provided with a driven friction wheel coaxial with the inserting shaft. The slide block can push the driven friction wheel to be in contact transmission with the driving friction wheel, and the edge of the circular blade cuts into the side wall of the tail end part of the rubber earphone hook.