In order to improve the wear resistance of CrN coating, magnetron sputtering technology was used to study the influence of external Cr layer on the wear width of CrN coating. The friction and wear of the surface were studied under different loads, rotational speeds and radii. The results show that the effect of centrifugal force is more obvious with the increase of rotation radius. When the rotation radius is 300r/min, the average wear width of the CrN coating without sputtering Cr layer reaches 945.7μm and the outer wear is more serious. Under the same conditions, the wear width of the outer Cr layer is 571.2μm. It shows that the outer Cr layer can effectively inhibit the increase of surface wear area during wear. After sputtering the outer Cr layer, the friction coefficient and the wear area width of the surface increase with the increase of the rotation radius at 200r/min. The wear marks on the surface are furrowed and the wear mechanism is abrasive wear.