A novel technique for quadratic phase shift three-point method based on data reconstruction and inverse filtering is proposed in this paper

through which the spindle radial motion error can be separated and gained firstly

and the on-line measurement of motion error can be implemented successfully. According to the principle of quadratic phase shift

data from die three probes can be reconstructed

the influence of roundness form error can be eliminated in the process of the first operation

and the radial error motion will be acquired in the second operation. Based on the comparative analysis of weighting function

the homology and unitarity can be proved by the proposed method for motion error measurement and the common three-point method for roundness measurement. Satisfactory results have been gained in some experiments and simulations.