Solution-processable indium oxide quantum dots (In2O3) were introduced into MAPbI3 film to solve the problem of low MAPbI3 film quality caused by inherent defects. Compared with MAPbI3 film, MAPbI3: In2O3 film exhibited optimized time-resolved photoluminescence component ratio and improved carrier dissociation and transport efficiency. When the MAPbI3: In2O3 film was used to fabricate solar cells instead of MAPbI3 film, the fill factor enhanced from 76.32% to 80.63%, short circuit current density increased from 20.18 mA/cm2 to 21.32 mA/cm2, power conversion efficiency improved from 13.96% to 16.18% in standard AM 1.5 illuminated condition, respectively.