摘要： This paper proposes an approach to the measurement, modeling, and compensation of the volumetric errors for three-axis machine tools, using the laser bidirectional sequential step diagonal measurement. Disparate measuring tracks are specially arranged for forward and backward paths, and the conforming error decoupling method is demonstrated. By decoupling, all the geometric errors which can result in the volumetric errors are distinguished simultaneously, containing translational and angular errors. In comparison with traditional unidirectional measuring method, the proposed bidirectional method distinguishes more geometric errors (the angular errors) by measuring the same four body diagonals. Uncertainty analysis based on the Monte Carlo simulation was conducted, followed by experimental validation on a vertical machining center. The experiment result indicates that the diagonal systematic deviation of positioning is reduced by 90% after volumetric compensation.