In order to overcome the shortcoming that the luminous flux of the classical spectrometer is small due to the occlusion of the entrance slit, a design concept of the new kind of Hadamard transform spectrometer is proposed. A method of shaping the beam by a cylindrical lens is given. Using theoretical calculations of the spectral resolution ability and the pixel resolution ability of the spectrometer, containing a digital micromirror array, he limit class of the spectrometer resolution can be determined. Based on the geometric theory of optical imaging, an optimization program of the more focal length of the imaging lens is proposed, which is able to obtain the higher spectral resolution and the more beneficial to the mechanical alignment. The advantages of the new Hadamard transform spectrometer are that it has a high luminous flux, the signaltonoise ratio is 5 times more than that of traditions, and the smaller spectral bandwidth is 3.5 nm, providing convenient conditions for the detection of weak spectral signal. In addition, the nearinfrared detector selected by the spectrometer needs no refrigeration, which will cut the production costs of the Hadamard transform spectrometer, with a stronger market competitiveness.