The combination of dye or quantum dots sensitized solar cell and electrochromic device has led to the realization of the photoelectrochromic device (PECD). In this study, a PECD consisted of carbon quantum dots (CQDs) sensitized photoanode, poly(3,4-(2,2-dimethylpropylenedioxy)thiophene) (PProDOT-Me-2) electrochromic film, Br-/Br-3(-) with Li+ as electrolyte was fabricated, and it shows advantages of highly transparency for bleached state when compared with conventional photoelectrochromic device. As a PECD, it exhibits a reversible optical modulation under constant illumination (100 mW cm(-2)) by simply altering its circuit states between on and off. A high optical window of 54.6% with coloration time of 4.9 s, and bleaching time of 5.2 s was achieved at 580 nm. Additionally, stable switching for transmittance modulation after 400 cycles demonstrates its good cycle durability, exhibiting great potential in developing energy-saving applications.