Abstract: The solvent toxicity and residual metal halides are the main factors restricting the application of the two-step preparation technology for perovskite thin films. By using green solvents to dissolve metal halides and adjusting the traditional two-step preparation procedure of perovskite thin films, the effects of preparation technological optimization on the properties of perovskite thin films were studied. The results shows that the green composite solvents can replace traditional toxic solvents for the preparation of perovskite films, and the photovoltaic conversion efficiency of perovskite solar cells based on the optimized two-step method reaches 15.92%.