The utility model provides a knife switch sander. The knife switch sander comprises an arc-shaped plate, a first sanding member and a handle, wherein the first sanding member is connected to the outer surface of the arc-shaped plate; the handle is connected with the arc-shaped plate and extends away from the arc-shaped plate along the axial direction of the arc-shaped plate. Through the adoption of the technical scheme of the knife switch sander, the knife switch sander is provided with the handle which is away from the arc-shaped plate, so the problem that an operator is not easy to touch the touch spots of a knife switch in the prior art is solved, and the labor intensity of the operator is reduced.