A method combining the triangulation measurement with multi-frequency grating is proposed. By fully using the three RGB channels of digital projector, the multi-frequency grating and dot array are projected on the surface of the object simultaneously. The extraction of the phase information modulated by height information is controlled comprehensively, and the 3D shape is obtained. In the simulation, when the high-frequency grating′s period shift caused by the step surface is up to 102 orders of magnitudes, the shape can be recovered. Experiments show that a 169 mm sharp height jump and 3 mm tiny details are recovered at the same time by using the method. The method improves the performance of traditional dual-frequency grating, and has the ability to handle larger step surface and maintain the high resolution, which greatly improves the Fourier transform profilometry (FTP) application performance.