Hybrid organic-inorganic halide perovskites (HOIP) hold promise in the field of optoelectronics due to their excellent photoelectric conversion efficiency. However, the ion migration and hygroscopicity of these perovskite solar cells need to be addressed. Here, we presented semitransparent perovskite solar cells (ST-PSCs) using HTL combined with polyaniline (PANI) to stabilize HTL/perovskite interface, achieving a humidity durability (RH, 50%–90%) for 596 days (14304 h) without encapsulation. Moreover, the decrease in hydrolysis products (LiF) showed the interaction between PANI with the additives in HTL dramatically inhibited the water uptake and corrosion on MAPbI3 layer. The PANI modified samples had a higher I/Pb ratio and lower trap state density, which indicated the passivation effect of PANI on the uncoordinated Pb2+ and iodine vacancies. Subsequently, PANI successfully stabilized the interface and perovskite by inhibiting the formation of Pb0 and Au migration as long period storage. This work presented an interfacial design to develop HOIP in air with high humidity stability.