Grinding apparatus

The utility model relates to a knife sharper, which comprises a support frame and a millstone. The utility model is characterized in that a baffle plate is fixed on one end of the millstone, a group of big tool steel sheets and a group of small tool steel sheets which have different diameters are respectively arranged on two shafts arranged in a groove arranged behind the baffle plate, the group of the big tool steel sheets are interlaced with the group of the small tool steel sheets, and the two groups of the tool steel sheets are arranged in the groove. An aluminum sheet is arranged on one end of the baffle plate near the millstone. The utility model can be made into a knife sharper with a moderate size according to the requirement, and is suitable for people using knife with left hand and right hand. One side of the grinded cutting edge has big gradient, and the other side has small gradient. The utility model has good effect.