Abstract: To develop the specialized software for cylindrical spur gear measurement on coordinate measurement machine (CMM), the measurement method of fixed involute cylindrical spur gear on CMM was studied. The mathematical model of the gear was established based on the basic parameters, and the theoretical coordinates and normal vectors of the characteristic points of the measurement of the tooth profile deviation and the tooth distance deviation were derived. After the probe calibration of CMM, the coordinate system of gear parts was established using iterative method. The motion path of the probe was planned and the measurement program was generated on the CMM. Then, the special software was developed to generate the PC-DMIS measurement code to realize the cylindrical spur gear measurement, and the profile and pitch deviations were evaluated in accordance with the gear accuracy standard. Relevant experiments were carried out, and the results show that the evaluation results of this method are in good agreement with the evaluation results of gear measuring center. The difference of pitch deviation with the biggest absolute value is 1.3 μm, and the difference of profile deviation with the biggest absolute value is 1.9 μm. This work developed a special software on the basis of the fixed involute cylindrical spur gear measurement method on CMM, and the gear profile deviations and pitch deviations were measured, which has certain reference significance for the secondary development of PC-DMIS on CMM for the complex profile precision parts measurement.