A study on the precision measurement method for the angular positions of the probes in roundness and spindle error motion with three-point method has been carried out in this paper.A measuring system has been developed

which can simply measures the angular positions of the nontouching capacitance micrometer gauges under real measurement.A correction method is proposed

which can eliminate the effect of the angular position measurement errors and the calibration errors of the capacitance micrometer gauges on the roundness and spindle error motion measurements.Experiments show that the measurement error of the angular position of the probes measured by the multiple line method proposed in this paper is less than 1′

and the effect of the angular position measurement errors and the calibration errors of the capacitance micrometer gauges on the roundness and spindle error motion measurements can be lessened to minimum.