A new method of three-dimension profile measurement is proposed based on infrared-light interference technology, which is extended from visible-light region to infrared-light region for white-light scanning interferometry. Microstructure with two steps of different heights is used to be demonstrative sample to prove the property of designed system based on linnik-type interferometric microscope with phase-stepping algorithm. Three-dimension profile and step height can be obtained accurately with GaAs wafer transmission compensation and are highly consistent with the results that obtained from the famous commercial instrument MSA 400. The novel method has widely potential applications in the field of MEMS, such as reconstructing the internal profile of encapsulation devices and analyzing the quality evaluation of bonding interface based on semiconductor materials.