The invention relates to a low-friction piston which comprises a cylinder sleeve, a piston rod, a piston sheet, a supporting frame, an installing nut and an installing gasket according to a technical scheme, wherein the piston rod is fixedly provided with the supporting frame through the installing nut and the installing gasket, the piston sheet is arranged on the supporting frame, an open-type annular groove is arranged on the outer wall of the piston shell along the circumferential direction, lubricating grease is filled in the annular groove, the groove opening of the annular groove faces away from the axle line of the piston rod; the piston sheet positioned in the annular groove is integrally provided with a plurality of annular convex edges which are arranged along the circumferential direction of the piston sheet; and a protecting film layer is adhered on the piston sheet in the annular groove. The invention has the advantages of low friction coefficient, long service life, better tightness and the like.