The invention provides a potato chip detumescence device and a using method thereof. The potato chip detumescence device comprises a shell with one end open, a sealing cover matched with the opening, a fixing mechanism used for fixing potatoes and a slicing mechanism used for slicing the potatoes, and the fixing mechanism comprises a fixator and a clamping ring in threaded connection with the outer circumferential wall of the fixator; the bottom end of the fixator is provided with an inserting needle inserted into a potato, a mounting hole is formed in the position, close to the opening, of the top of the shell, the clamping ring is fixedly connected with the mounting hole, sliding grooves are formed in the two side walls, opposite to the opening, of the shell, and the slicing mechanism comprises a fixing block, a blade and a pull rod. The two ends of the fixing block are provided with fixing shafts matched with the sliding grooves, the blade is fixed to the side, facing the opening of the shell, of the fixing block, and the two sides of the blade are provided with fixing rods connected with the fixing block. According to the potato chip detumescence device, potatoes can be conveniently sliced, potato slices can be conveniently fixed to the human body, and the potato slices can be prevented from being polluted.