Abstract: A phase unwrapping method based on multi-frequency heterodyne principle by projecting four different frequency fringes was deduced. Meanwhile, In order to reduce the phase unwrapping errors, a phase correction method was proposed, and the effect on matching result was compared before and after phase correction. In order to improve the accuracy of the matching, the revised absolute phase value was used as the basis for matching. Besides, the subpixel matching algorithm was utilized based on phase linear interpolation.Finally, the 3D reconstruction technology was used to obtain the three-dimensional point cloud. Results show that the matching rate of plane measurement is increased by 4.97%, with the measurement accuracy of 0.189 5 mm .