Although three-dimension (3D) shape measurement based on digital grating projection has a good development prospect, the problem of high accuracy measurement cannot be solved. Combing with height-phase mapping and lattice calibration, a 3D measurement method is proposed. The Geometric constraints of digital-grating and CCD are decreased. The measurement system is more feasible, which can be used to realize the accurate measurement and reconstruction according to the 3D information of measured object. By applying the proposed method to measure a 20.00 mm height reference object, the relative error is 0.727 5%. The experimental result shows that the method is efficient and precision.