Herein, we used Prussian blue (PB) as an indicator for self-powered electrochromic visual sensing driven by photoelectrochemical (PEC) cell to detect prostate specific antigen (PSA). The sensor consists of a photoanode and a PB/ITO cathode. Under the visible light excitation, photoelectrons generated from the photoanode will transmit to PB through an external circuit, making the blue PB reduced to transparent Prussian white (PW). In the presence of PSA, the transfer rates of photoelectrons slow due to steric hindrance, leading to different fading degree of PB. Moreover, the color intensity of PB is proportional to the concentration of PSA, we can quantitatively detect the PSA according to the color intensity. Under the optimal conditions, the linear range of detecting PSA was 0.1-50 ng/mL with the detection limit of 0.03 ng/mL (S/N = 3). Meanwhile, the prepared novel sensing platform exhibited great selectivity and provided a rapid, visual method for PSA detection in human serum, which has great application prospects in point-of-care (POC) diagnostics.