The present invention discloses a wheel machining technology in which blank quantity is furthest removed by using a 90-degree external turning tool. Under the premise that the rotation direction of a wheel is unchanged, an upper trench of a groove is processed by using a left-handed special cutting-off cutter. Under the premise that the rotation direction of the wheel is unchanged, a lower trench of the groove is processed by using a right-handed special cutting-off cutter. The left-handed special cutter and the right-handed special cutter are added to the wheel machining technology disclosed by the present invention, so as to complete the processing of a groove of an outer wheel rim; a processing program can be pre-edited, so that processed effects conform to the design requirements of drawings of products.