Abstract: This article studies the film-forming process of flexible perovskite solar cells（FPSCs）,and analyzes the reasons and influencing factors for the uneven deposition of thin films,numerous defects,and internal stress on flexible substrates. PET/ITO is selected as the flexible substrate,SnO2as the electron transport layer,and KCL is introduced for regulation. The introduction of KCl increases the affinity between the electron transport layer and the flexible conductive substrate,resulting in a dense and defect free film layer. By optimizing the distribution ratio of perovskite precursors,introducing MACl as an additive to regulate the crystallization process,and designing a PEAI passivation layer passivation interface on the surface of perovskite,high-quality perovskite crystals and dense surfaces are obtained,and the flexibility performance of the device is improved. In a suitable environment,a flexible perovskite cell with a certified efficiency of 23.14% was prepared,and the initial conversion efficiency of 80.48% can still be maintained after10000 time bends.