The atmosphere sounding′s principle of limb and nadir detecting modes are discoursed, and the prototype of ultraviolet (UV) annular imager with fire-new detecting modes is designed, which can gets the earth limb and nadir images of atmosphere simultaneously on the near-earth orbit. The prototype has a refraction-reflection optical system, and its spectral ranges are 285～395 nm, 305～315 nm and 350～360 nm. It can realize the image sounding with multiple azimuths by earth′s limb mode (the vertical height of the atmosphere is from 0~120 km)and 10° field of view by nadir mode, and the data received can be used to retro-deduce the spatial distribution and the dynamic state configuration of the atmospheric radiation within multiple azimuths. The performances for 310 and 355 channels of the prototype are tested. The results show that the spatial resolution and the signal-to-noise ratio are both satisfied the design requirements and it is suitable for the application of the space UV remote sensing.