键槽对轴（孔）中心线的对称度误差直接影响键联结的质量。着重介绍轮毂槽对称度误差的产生、测量方法、计算公式及推导，并给出了测量实例。 The asymmetry of the keyway to the shaft (hole) centerline directly affects the quality of the keyed coupling. Emphasis is put on the generation, measurement method, calculation formula and deduction of the wheel groove symmetry error, and the measurement example is given.