Based on the working principle of analyzing spectrometer and the theory of optical design, to make the system miniature, and with a certain spectral range and resolution requirements as specific design objectives, a cross-C-T micro-structure based on a plane diffraction grating spectrophotometer of the near-infrared spectrometer was put forward; ZEMAX was used for design and optimizing and simulating analysis of micro-near-infrared spectrometer in the optical system. The result showed that the micro-optical system’s spectral range was 900-1 700 nm, resolution was ＜10 nm, spectrum broadening was 12.74 mm, F number was 8.128 388, and the system volume was 51.26 mm×41.81 mm×22 mm, and these all satisfy the requirements. It solved the micromation of the optical system of the spectrometer, and therefore, contributed to the micromation of the spectrometer itself.