An analysis model for Digital Micromirror Device(DMD) of optomechatronics integration element is proposed, and the theoretic angle of diffraction is obtained by using LightTools to simulate optimization of the analysis models. and then comparing the theory angle with the result of the experiment.The results of the experiment and the simulation conclusion are consistent with each other very well.We have designed a Hadamard transform spectrometer which based on this diffraction model.And then we test the spectrometer by Halogen lamp source: the resolution ratio of the spectrometer can achieve 8 nm, signal-to-noise ratio can achieve 1 366, the center wavelength drift is only 0.408 nm, and the single acquisition time is only 0.8 second, these results show that the spectrometer has good resolution ratio , good signal-to-noise ratio, good stablity,good repeatability and good real-time ablity. The spectrometer is very good to overcome the traditional Adama spectrometer poor shock resistance, acquisition speed, low precision, has the very high market potential.