To verify whether the ground ultraviolet detection system can be used to detect the high altitude and high speed reentry targets above the ozone layer, mechanism research of UV radiation caused by high altitude high speed reentry target and feasibility of ground UV detection are studied, and in the return test of the shrinked ratio cabin of a multipurpose spacecraft, an equipment of UV optical imaging is used to carry out the verification test, which obtained above 40 km of high altitude and high speed reentry target surface UV detection image, broke the blank record of ground optical detection which had never get UV image of high-altitude above ozone layer of high speed target. The results show that under the condition of thin atmosphere, the high altitude high speed target can produce strong ultraviolet radiation. And it is feasible to use the ground ultraviolet detector to detect the high altitude high speed reentry target. Moreover, the imaging target can be effectively separated and extracted from the background. It has the important reference value for the further development on practical application and further research on the theory of ultraviolet detection.