All-inorganic halide perovskite solar cells(PSCs)have acquired great progress,especially CsPbI2Br.However,their photoelectric conversion efficiency(PCE)remains far below the theoretical predictions.Non-radiative recombination is one of the important issues affecting the photoelectric performance of the PSCs,and the defective lead ions derived from the evaporation of halide ions in the inorganic per-ovskite are the principal non-radiative recombination centers.Herein,the non-radiative recombination is effectively suppressed by introducing the N-methyl-2-pyrrolidone(NMP)as a Lewis base molecule to passivate the defective lead ions.Therefore,by adjusting the dosage of NMP,the smooth and pinhole-free CsPbI2Br perovskite film is obtained and the optimized device exhibits a champion PCE of 16.77％with an excellent fill factor(FF)of 0.80.This work proves the effectiveness of passivation using Lewis base molecules to prevent non-radiative recombination defects in inorganic perovskite.