ZnO microrods with (100) orientation were successfully grown on carbon fiber paper (CFP) substrates via a hydrothermal method. The crystal structure and morphology were systematically characterized by X-ray diffraction, Raman spectroscopy, and field-emission scanning electron microscopy. A photoelectrochemical self-powered ultraviolet photodetector (PEC-PD) based on the ZnO/CFP composite was fabricated, and its optoelectronic properties were thoroughly investigated. Results demonstrate that the ZnO Microrods exhibit excellent crystalline quality with high crystallinity. The fabricated ZnO/CFP PEC-PD shows outstanding self-powered photoresponse under UV illumination, including a remarkable photo-to-dark current ratio (8.82×10 2), high responsivity (7.34 mA·W-1), fast response times (rise time is 0.17 s， fall time is 0.18 s), good wavelength selectivity, and stability. This work proves the great potential of hydrothermally synthesized ZnO/CFP PEC-PDs in self-powered UV detection applications, providing valuable insights for developing high-performance self-powered photodetectors.