In this study, a wide-coverage and high-resolution airborne camera optical system is designed for wide-area and efficient aerial work demand of airborne camera. The optical system adopts a novel cascade structure of optical imaging consisting of a fore monocentric symmetric objective and a relay lens array. The fore monocentric symmetric objective obtains a wide field-of-view curved surface image with uniform residual aberrations. The relay lens array simultaneously performs the field-of-view subdivision, residual aberration correction, and relay imaging for the curved surface image. The optical system in the designed airborne camera has 60 mm focal length, 3.4 F number, and 132° field-of-view angle. The relationship between the imaging performance of the airborne camera optical system and the wide-field curved image at different flight altitudes is studied herein based on the first-order theory and aberration characteristics. A method for achieving clear imaging at different flight altitudes is also obtained. The image performance evaluation results show a good image quality when the optimized design system performed ground observation at low, hollow, and high altitudes. The modulation transfer function reaches 0.4 at the Nyquist frequency of 230 lp/mm, and the root mean square radius of the system's ray tracing spot diagram is less than 1.6 μm, verifying that the designed cascade optical imaging system is suitable for airborne cameras with different flight altitudes.