A flexible self-powered ultraviolet (UV) detector based on ZnO nanowires has been fabricated for the first time. The assembled UV detector shows good performance both in flat and bending conditions, which is important for future wearable and flexible optoelectronic applications. The responsivity of the fabricated device has improved by 44% after the decoration of Ag nanoparticles. Such enhancement is attributed to the modified structure which facilitates light absorption.