Abstract:Coordinate measuring machine (CMM) has been widely used in machining, automobile, electronics, aerospace and other fields due to its advantages of intelligence and high efficiency. The measurement accuracy is particularly critical, and one of the important index is the indication error. So it is necessary to strictly control each variable in the calibration, and get the accurate indication error to evaluate the comprehensive measurement accuracy of CMM. In this paper, some problems caused by temperature, probe information and attitude of measuring block in the calibration of CMM are analyzed, and the solutions are put forword. Finally, the measurement uncertainty of the indication error is evaluated, which provides reference for the calibration of CMM.