Space-based atmospheric remote sensing urgently require UV panoramic imager. The research objective is sounding nadir and limb atmosphere simultaneously. Based on this research objective, a new optical system construction of UV panoramic imager is proposed, in which, the nadir Field of View (FOV) and limb FOV use a common image plane. An optical system of panoramic imager is designed, the central wavelength is 360nm, the bandwidth is 10nm, the nadir FOV is 10°, the limb FOV is 360°×(70.31°～72.71°), the focal length is 5mm, an the relative aperture is 1: 3.3. The energy of margin FOV is increased by using the distortion of the optical system, and the image irradiance is increased by using the effective aberration vignetting caused by pupil aberration. The relative illumination of margin FOV is more than 98% of that of central FOV. The multi-configuration is established with the optical paths of nadir FOV and limb FOV. The optical paths of nadir FOV and limb FOV is optimized by using multi-configuration optimization function of ZEMAX-EE software. The design result shows that the MTF of nadir and limb FOV are both more than 0.6@38.5lp/mm, The design requirements are satisfied. The volume of the panoramic imager is small, and is suitable for appplication in space.