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 radius. The results show that the effect of centrifugal force is more obvious with the increase of rotation radius. When the rotation speed is 300 r/min, the average wear width of the CrN coating without sputtering Cr layer reaches 945.7 μm and the outer wear is more serious. Under the same conditions, the wear width of the outer Cr layer is 571.2 μm. It shows that the outer Cr layer can effectively inhibit the increase of surface wear area. When the outer Cr layer is being sputtered, the friction coefficient and the wear area width of the surface increase with the increase of the rotation radius at 200 r/min. The wear marks on the surface are furrowed and the wear mechanism is abrasive.