The invention discloses a grinding mechanism of a coffeemaker, which is internally provided with a bean cabin, a grinding body is arranged under the bean cabin and internally provided with a rotatable millstone and a static millstone, the two millstones are both provided with grinding gears, the rotating shaft of a grinding motor is connected with the rotatable millstone, and a powder outlet channel is arranged under a meal outlet. The static millstone is fixed on a static millstone frame which is fixed on a connecting piece, the periphery of which is provided with screw thread, the connecting piece is screwed on the grinding body; and the rotatable millstone is connected with the rotating shaft by a rotatable millstone frame. The bean cabin, the static millstone frame and the static millstone can be dismounted from the grinding body by the grinding mechanism of the invention, thus leading the cleaning of remaining coffee powder in the grinding mechanism to be extremely convenient. When in use, the bean warehouse, the static millstone frame and the static millstone are screwed into the grinding body, and then the bean grinding operation can be carried out.