The invention discloses an abrasion-resisting coating of a piston ring. The abrasion-resisting coating is composed of a four-layer structure sequentially comprising a bonding layer, a main abrasion-resisting layer, an auxiliary abrasion-resisting layer and a buffer layer from inside to outside. The main abrasion-resisting layer is a CrAlN/WS<2> multi-layer coating alternately formed by CrAlN layers and WS<2> layers. The auxiliary abrasion-resisting layer is a Cr/CrO multi-layer coating alternately formed by Cr layers and CrO layers. The abrasion-resisting coating of the piston ring has the advantages that excellent mechanical properties, tribological properties and corrosion resistance are achieved, energy consumption of friction and abrasion is reduced, and the fuel economy is improved, and CO2 emission is reduced; and the CrAlN/WS<2> multi-layer coating with high hardness and the low friction coefficient is adopted as the main abrasion-resisting layer, work stability of an engine isfurther improved, and the service life of the engine is further prolonged.