CsPbBr 3 all-inorganic perovskite solar cells (PSCs) have been extensively investigated due to their remarkable stability. However, their limited film quality and wide bandgap result in a low photoelectric conversion efficiency (PCE). In this study, BiI 3 was incorporated into CsPbBr 3 films to synergistically enhance light absorption and film quality. It was found that the partial substitution of Pb 2+ and Br - with Bi 3+ and I - in CsPbBr 3 improved film quality, enhanced light absorption, and facilitated charge transfer and extraction. The device incorporating BiI 3 -incorporated CsPbBr 3 as a light absorbing layer achieved an efficiency of 9.54%, exhibiting a significant enhancement of 19.4% compared to the undoped device. This work provides a new incorporating strategy that collaboratively improves light absorption and film quality.