A compensation method for the positioning error caused by the deformation of the load cell was proposed. For the electromagnetic centerless clamp grinding bearing ring, the load cells were installed on the front and rear supports respectively. When supporting the radial positioning bearing ring, the load cell accurately measures the supporting force of the bearing ring and shifts accordingly. By analyzing the positional relationship between the centerless grinding support and the workpiece and the change law of the positioning error during the grinding process, the calculation formula of the positioning error caused by the offset of the support caused by the force deformation of the load cell was deduced, and it was proposed to control the grinding wheel carriage feeding to compensate the positioning error. The results show that the deformation of the load cell will affect the machining accuracy of the ring;this method can be used to compensate the positioning error. The comparison of the grinding time before and after compensation shows that the method can improve the cylindrical grinding efficiency of the bearing ring.