For the problems of measuring methods,based on the measurement status and processing status consistent detection principle,the enveloping worm precision measuring principle is designed.According to the automatic calibration procedure and the high-precision time grating turntable,so that the three-dimensional measurement coordinate system is created automatically by the system,and the probe radius of gyration is measured by using the coordinate rotation method.By using servo control method to measure the enveloping worm tooth surface coordinate values of each measurement point in the coordinate system,and the enveloping worm accuracy is obtained.The pyramidstyle structure is used to makes the system more stable,reliable.The experiments show that the feasibility of the program,and the measured accuracy of enveloping worm helix reached±4μm.Repeating the same precision experiments of system,the range of system reached 0.9μm,the variance analysis shows that the error value of each measurement point is no significant difference.