Method for preparing perovskite solar cell

A method for preparing a perovskite solar cell is disclosed, which comprises the following steps: providing a first electrode; forming an active layer on the first electrode; and forming a second electrode on the active layer. Herein, the active layer can be prepared by the following steps: mixing a perovskite precursor and a solvent to form a precursor solution, wherein the solvent comprise a first solvent and a second solvent, the first solvent is selected from the group consisting of [gamma]-butyrolactone (GBL), dimethyl sulfoxide (DMSO), 2-methylpyrazine (2-MP), dimethylformamide (DMF), 1-methyl-2-pyrrolidone (NMP) and dimethylacetamide (DMAc), and the second solvent is an alcohol; and coating the first electrode with the precursor solution and heating the precursor solution to form the active layer.