Dendriform titanium dioxide nanowires (D-TiO2 NWs) with high aspect ratio and density serve as a model architecture for high-performance self-powered ultraviolet (UV) detectors. The photo-sensing performance is characterized by integrating D-TiO2 NWs into a photoelectrochemical cell. The short-circuit current density value of the D-TiO2 NWs based UV detector is 176% and 46% higher than that of the bare TiO2 NW film and TiO2 nanocrystalline film since it offers excellent ultraviolet absorption, efficient charge carrier separation and fast electron transport. The incident power conversion efficiency can reach 14.5%, which promises a high sensitivity to the UV light. Under UV irradiation, the detector made of D-TiO2 NWs exhibits a high responsivity of 0.61 A/W, a high on/off ratio of 1903 (incident power density 25 mW cm−2) and a fast response time of 5.9 ms. Combined with visible-blind characteristics and photosensitivity linearity in wide light intense range, the D-TiO2 NWs based self-powered UV detector demonstrates promising application in various fields.