In this paper, the application of harmonic diffractive element（HDE） in the infrared hyperspectral detection system is investigated based on the special large dispersion capability of HDE and window character of infrared bands. The fundamental principle of the new infrared hyperspectral imaging is described, and a design sample is presented. It is shown that the resolution is improved and the optical power received is enlarged. The rectification of the ray aberrations in both band has been simultaneously accomplished. Wave front aberrations are less than 1/4 wavelength,and the modulation transfer function of the dual-band in every zoom focus location approaches or attains the diffraction limit of 20 cycles/mm.