Aiming at the problem of increasing the number of optical elements and limiting the angle of view to balance the aberrations in the current optical design, which makes the optical system more complex, a design method of harmonic diffractive lenses based on the infrared waveband with a large field of view is proposed. The optical design software ZEMAX was used for optical design, a customizable surface profile was written using DLL, and this surface was used for partition optimization, and combined with scalar diffraction theory, the imaging effect was analyzed. The results show that the designed harmonic diffractive lens has a field of view of 21°, and the cutoff frequency (with 0.1 as the contrast limit) is 11.4lp/mm, and the feasibility of the lens with a large field of view single lens imaging is verified through experiments.