The invention discloses a trace Sn-doped perovskite membrane repair preparation method and an all-inorganic perovskite solar cell. The preparation method comprises the following steps of dissolving tin halide and lead halide into a DMF solution to form a substrate solution; spin-coating the substrate solution onto the surface of a substrate, and drying the substrate solution on the surface of thesubstrate to enable the surface of the substrate to form a substrate layer; dissolving cesium halide into DMSO to form a modified solution, wherein the modification solution is spin-coated on the substrate layer repeatedly, the heating is performed after each spin coating is completed, and the modification solution and the substrate layer are gradually reacted to form the all-inorganic perovskitelayer. The tin halide has a damage effect on a film formed by the original lead halide, so that the substrate layer becomes a loose porous structure, the reaction of cesium halide and lead halide is facilitated, and the reaction area between cesium halide and lead halide is increased; and after cesium halide reacts, the pores are gradually filled up, and the obtained all-inorganic perovskite layerhas fewer needle holes and shows more excellent charge extraction capacity and charge transfer capability.