提出一种将三角法测距与多频光栅相结合的方法，充分利用数字投影的RGB通道，将多频光栅与点阵同时投影在物体表面，综合控制受高度调制的相位信息的提取，最终获取物体的三维形貌。仿真结果显示，在高度跳变使高频光栅位移达102量级个周期时，可以准确还原原始形貌。通过实验验证，本方法能够同时复原169 mm的陡峭高度跳变以及3 mm的微小细节，提高了传统双频光栅的性能，具有处理较大截断面和保证细节部分的测量能力，较好地改善了傅里叶变换轮廓术(FTP)的应用性能。

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.