Air-processed perovskite solar cells (PSCs) expediate its commercialization. However, since the intrinsic moisture sensitivity disturb perovskite crystallization and morphology, the photovoltaic performance and shelf stability attenuation are inevitably occurred. Herein, 1-ethy-3-methylimidazolium tetrafluoroborate ([AOEMIM][BF4]) ionic liquids (ILs) was incorporated into perovskite interior to weaken the deleterious influence of ambient moisture on perovskite crystallization. The carboxyl and imidazole from the [AOEMIM]+ moiety passivate undercoordinated Pb2+ defects through coordination bond, while hydrophobic [BF4]- incorporating into the precursor solution protects the films from moisture destruction. Consequently, the targeted PSCs fabricated in open air achieved an impressive PCE of 19.86 % with favorable shelf stability, maintaining 93 % and 89 % of their original efficiencies after 720 h under relative humidity of 80 ± 2 % and after 240 h thermal ageing measurement at 85 °C, respectively.