Abstract: To enhance the long-term stability of organic-inorganic metal halide perovskite solar cells（PSCs）with silver as the rear electrode,the technique of depositing a indium tin oxide（ITO）layer between the molybdenum oxide layer and the silver back electrode using radio frequency magnetron sputtering for inner encapsulation of PSCs has been studied. To prevent damage to the pre-deposited perovskite layer and organic hole transport layer caused by the ITO layer sputtering,the effects of the sputtering power and the thickness of ITO layer on the photovoltaic performance of PSCs are studied,and an optimized ITO layer preparation process is obtained. It is found that the photovoltaic performance of PSCs is optimal when the sputtering power and the thickness of ITO layer is 30 W and 40 nm,respectively. To further improve device performance,the effects of sputtering and thermal evaporation methods for depositing silver rear electrodes on device performance are analyzed. It is found that compared with thermal evaporation method,PSCs with sputtering silver rear electrode has better photovoltaic performance and achieves a power conversion efficiency of 17.86%. The long-term stability testing and X-ray diffraction analysis of the device indicate that the insertion of the sputtered ITO barrier layer can effectively suppress the diffusion reaction between halogen ions in the perovskite layer and the silver back electrode,significantly improving the stability of the PSCs without reducing the device efficiency. After being stored in dry air for 4500 hours,the prepared PSCs with the sputtered ITO barrier layer can still maintain 95% of its initial efficiency.