The method discloses a flexible CIGS/perovskite stacked solar cell preparation method and belongs to the field of solar cells and energy technologies. The flexible CIGS/perovskite stacked solar cell is composed of a stainless steel (SS) substrate (1), a metal back electrode (2), a CIGS absorption layer (3), a CdS buffer layer (4), a window layer (5), an intermediate composite layer (6), a cavity transmission layer (7), a perovskite phase absorption layer (8), an electron transfer layer (9) and a transparent electrode (10) in sequence. The cell of the structure is beneficial for charge balance extraction, the retardation effect of the current-voltage curve is inhibited, and the fill factor and the photoelectric conversion efficiency of the cell are improved; and the all-inorganic material structure improves the operation stability of the cell. Magnetron sputtering and a selenylation method are adopted to prepare the CIGS layer, spraying and a semi-vapour deposition method are adopted to prepare the perovskite layer, and the method provided by the invention is beneficial for large-scale production and preparation of large-area solar cells.