Abstract <p>Traditional three-axis coordinate measuring machines often face limitations in measurement efficiency, hindering their application in high-speed manufacturing environments. This study proposes a novel comparator design based on a parallel mechanism, aiming to enhance measurement speed and precision in geometric inspection tasks. A comprehensive kinematic analysis and spatial simulation of the proposed parallel mechanism comparator were conducted to validate its performance advantages. Initially, a detailed model of the parallel mechanism comparator was established, accompanied by the construction of a spatial coordinate system. Utilizing screw theory, the mechanism’s degrees of freedom were rigorously analyzed to ensure optimal mobility and constraint conditions. Subsequently, inverse kinematic equations were derived, enabling the computational filtering of coordinate points that satisfy system constraints. The workspace of the mechanism was then mapped, with particular emphasis on investigating the influence of motor stroke length on the reachable spatial volume. Finally, kinematic simulations of the actuator-driven parallel mechanism were performed to assess output stability and dynamic behavior. The results demonstrate that the designed parallel mechanism comparator achieves an extensive workspace and exhibits stable actuator performance, confirming its potential to significantly improve measurement efficiency. This work not only provides a theoretical foundation for high-speed, high-precision geometric inspection but also suggests promising applications of parallel mechanisms in the medical diagnostics field as a key enabling technology.</p>