The imaging and dispersion characteristics of membrane diffraction primary lens were studied, and the strong dispersion of diffraction primary lens was corrected by using the reflective achromatic optical light path with diffractive optical surface. Thus, the membrane diffractive optical system with an aperture of 10 m and a total length of 115.73 m was designed with the waveband of 40 nm, the field of view of 0.02°. The results show that, the focal length difference between the two edge wavelength of 0.58 μm and 0.62 μm decreases from 5.34 m to 17.27 μm by uing the achromatic optical path. This study presents a design method for the imaging system with membrane diffraction primary lens, which can provide references for the engineering research of the large aperture membrane diffraction imaging system.