Scanning grating micromirror is a new generation core diffraction component of micro spectrometer. However，due to using of linear sensor which is too expensive in near infrared， the application of near infrared spectrum analysis technology is seriously restricted. In this paper， we present an electromagnetic scanning grating micromirror which is fabricated by Micro-Electro-Mechanical System（MEMS） technology. This device integrates with grating， driving actuator and angle sensor. It can replace array detectors with single detector. First， we design the theoretical model， and analyse the impact of main structural parameters such as beam size and mirror size on device performance. Based on these， the optimized design parameters for scanning grating micromirror are obtained. Subsequently， we fabricate this device by MEMS technology and test its performance. The experimental and theoretical results show that when the scanning angle is ±7^o，the spectral range is 800-2 500 nm，the diffraction efficiency near the blazed wavelength is ≥70%， and the control precision of angle sensor is ≤ 0.05^o， This result demonstrates that the using of our device in micro spectrometer is effective.