The conventional NIR spectrometers based on fixed grating and array detectors have disadvantages of high cost and narrow spectral range. To address these issues, the dual single detectors NIR micro spectrometers are proposed, which are based on integrated scanning grating micromirror. This system employs the integrated scanning grating micromirror as the core component, which can realize the scanning and diffraction simultaneously. The spatial layout of two focusing mirrors and dual InGaAs single detector are utilized to avoid the mutual interference between different optical paths in the optical system design. It can realize the simultaneous and independent operation of two optical paths. In addition, a band-pass filter with different cutoff wavelengths is established in front of the dual-path detectors to eliminate spectral overlap. A theoretical model is formulated by the ray tracing method to calculate the structural parameters of the optical system. The optimized design of the optical system is achieved by using ZEMAX and the optimal structural parameters are given. Test results show that the operating wavelength range is 800~ 2 532 nm. Resolution is smaller than 12 nm (800~ 1 600 nm) and 17 nm (1 600~ 2 532 nm), and the overall size is 145 mm×135 mm×75 mm. This instrument has the advantages of wide spectrum, small volume, low cost and other advantages.