To effectively detect ultraviolet （UV） light without an external power source， a self-powered UV photodetector （UVPD） was developed using Ag/Bi₂O₃ nanoblocks. Initially， Bi₂O₃ nanoblocks were prepared through a calcination process， followed by the successful synthesis of Ag/Bi₂O₃ nanoblocks by depositing Ag nanoparticles on their surface via a solution reaction method at room temperature. The crystal structure and microstructures of the samples were analyzed， revealing that the Ag/Bi₂O₃ nanoblocks had an average diameter of approximately 1 μm， with Ag nanoparticles randomly distributed on the surface of the Bi₂O₃ nanoblocks. The Ag/Bi₂O₃ nanoblocks were then coated on FTO as the working electrode， leading to the construction of the self-powered UVPD. Upon exposure to UV light （365 nm）， the Ag/Bi₂O₃ nanoblocks UVPD quickly detected UV light at zero bias voltage， showcasing its self-powered capability. Compared to the Bi₂O₃ nanoblocks UVPD， the Ag/Bi₂O₃ nanoblocks UVPD displayed significantly improved photocurrents， with rise and decay times reduced to 29.1 ms and 40.2 ms， respectively， and demonstrated excellent cycling stability.