The CNC Machining center‘s opinion is as follows: the reverse error (loss of momentum) of linear motion, including the reverse dead zone of the drive part (such as servo motor, servo hydraulic motor and stepper motor, etc.) on the coordinate axis feed transmission chain, the comprehensive reflection of the errors such as the reverse clearance and elastic deformation of each mechanical motion transmission pair. The larger the error, the lower the positioning accuracy and repeated positioning accuracy. The detection method of reverse error is to move a distance in the forward or reverse direction in advance within the stroke of the measured coordinate axis and use this stop position as a reference, and then give a certain movement command value in the same direction to move a certain distance, and then move the same distance in the opposite direction to measure the difference between the stop position and the reference position. Measurements are performed multiple times (usually 7 times) at three positions near the midpoint of the stroke and at both ends, and the average value at each position is obtained. The maximum value of the resulting average value is the reverse error value.