In this study, a solar-blind ultraviolet single-photon imaging system was developed. The laser three-dimensional imaging was realized within a distance of 0--400 m with 22-mm imaging precision by combining the single-photon detector with Geiger-mode Si avalanche photodiode (Si APD) and the time-correlated single-photon counting technique. In the experiment, a 266-nm pulsed laser source was used, which is in the solar-blind band. Due to the atmospheric absorption, there is no background light noise at 266-nm wavelength on the surface of the Earth. This significantly improves the antibackground noise ability of the single-photon imaging system. Thus, this system can be operated on a sunny day to realize all-day single-photon imaging within a middle-long distance.