High-performance near-infrared spectrometer has a very high demand for wavelength accuracy，generally less than 0.2 nm，and requires high-precision motor and control system to realize. The use of DC motor drive grating rotation，control system is complex，high cost，with the development of stepper motor technology，the use of simple structure，low cost and high-precision stepper motor drive grating rotation has become possible. In this study，based on the S450 near-infrared spectrometer produced by Shanghai Lengguang Technology Co.，Ltd.，the two-phase stepping motor with double gear structure is replaced by a five-phase stepping motor to directly drive the grating，and the linear fitting method is applied to deduct a certain number of subdivision steps of the motor to eliminate the wavelength shift generated during the reverse back scanning. The results show that the grating is directly driven by a five-phase stepping motor，which can be utilized for forward and reverse scanning to improve the efficiency and at the same time meet the wavelength accuracy requirements of high-performance near-infrared spectrometer，which is less than 0.05 nm at the CH one-fold absorption peak of about 1 730 nm，and compared with the plus-gear-driven structure，there is no wear and tear of gears，and the service life is prolonged. This study not only can significantly improve the performance of domestic NIR instruments，but also provides an important reference for the application of five-phase stepping motors in analytical test instruments.