An ultraviolet single photon imaging system was built and its structure,working principle and spatial resolution are reported. Ultraviolet single photon can be obtained by ultraviolet lighr emitted by a mercury lamp and is attenuated by filters. Single photon irradiates on the microchannel plate directly, producing the multiplied electrons. The multiplied electrons are collected by wedge and strip anode. The charge signal coming from the anode is transformed to voltage signal by a charge_sensitive preamplifier. Then the voltage signal is filtered and shaped by a main amplifier. The output wave signal is collected by high speed data collection card continuously and processed with software. Finally, a ten-minute counting image of ultraviolet single photon is acquired and its revised image is obtained by image processing. The spatial resolution of this system can reach 150 micrometers as tested with the self-designed resolution board. The system can be used widely for very faint luminescence detecting/imaging, biological luminescence and space environment weak light detection.