Abstract: In this study,the influence of introducing MoO₃hole modification layer between hole transport layer Spiro-OMeTAD and Ag electrode on the photovoltaic performance of the blade-coated perovskite solar cell device was investigated.The mechanism was examined through a series of tests encompassing electrical conductivity measurement,steady-state photoluminescence spectra,contac angle with water,etc.The results of experiments and tests indicate that MoO₃can effectively improve hole transport capability and reduce interfacial resistance while protecting the underlying Spiro-OMeTAD and perovskite layers from water and oxygen degradation in the air.Based on MoO₃interface modification layers,the blade-coated perovskite solar cell device’s photovoltaic conversion efficiency increases from 15.14%to 18.30%,especially the average fill factor rises from 60%to 76%.At the same time,the stability of devices is also improved,with the unpackaged device still maintaining 90%of it initial efficiency after 400 hours.