ZnO thin film was prepared by direct current (DC) magnetron sputtering, whose properties were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and ultraviolet-visible spectrometer (UV-Vis). The photocurrent characteristics of the metal-semiconductor-metal (MSM) photoconductive ultraviolet detector with Au/ZnO/Au structure based on ZnO film were investigated. The results showed that ZnO UV detector had a higher photocurrent of 2.5 mA under the typical responsivity peaked at around 360 nm, the dark current was 250 μA with the applied bias of 5 V. In addition, ZnO UV detector also had a higher photocurrent at the wavelength from 250 nm to 380 nm, and photoresponse obviously reduced between 380 nm and 430 nm. And a slow photoresponse with a rise time of 20 s and a decay time of 80 s was achieved. The ratio of UV (360 nm) photoresponse to visible (450 nm) one is about three orders from the spectra response. The neutralization of photogenerated holes by negatively charged oxygen ions plays a key role in the photoconductive characteristics of ZnO films.