An apochromatic objective with a middle field of view and a large relative aperture was designed to satisfy the imaging demand of hyper-spectral imager from 365 nm to 1000 nm bands.Based on the primary aberration theory,the dispersion properties of glass materials in the visible and near infrared bands were analyzed,which provides a reference for the selection of glass materials in optical design.The results of optical design show that through the rational use of fluorine crown glass,chromatic aberration has been corrected successfully,and secondary spectrum is only 0.014 mm.The objective has a focal length of 18 mm,a relative aperture of 1∶2.4 and a field of view of 30°,and the imaging quality is close to the diffraction limit,which meets the design requirement of hyper-spectral imager.