The invention discloses a preparation method for a novel copper-bearing ionized perovskite thin film. The preparation method comprises the steps that firstly, CH3NH3X (MAX) is dissolved in a DMF solvent, and stirring is carried out until CH3NH3X is dissolved completely; secondly, an HCl solution is added; thirdly, CuI is added, and stirring is carried out; fourthly, PbI2 is added, stirring is carried out under a shading condition, and a copper-bearing ionized perovskite precursor solution is obtained; fifthly, a substrate material is washed; sixthly, the washed substrate material is put in an ultraviolet ozone washing instrument to be washed; seventhly, the copper-bearing ionized perovskite precursor solution is dropped onto the substrate material, and then spe in coating is carried out; eighthly, the spin coated material is heated and then is cooled to the room temperature, and the copper-bearing ionized perovskite thin film is obtained. The prepared copper-bearing ionized perovskite thin film is good in stability, low in cost, free of toxicity and high in photoelectric conversion efficiency. The copper-bearing ionized perovskite thin film can serve as an efficient photovoltaic energy material, photovoltaic power generation cost is greatly reduced, and therefore the copper-bearing ionized perovskite thin film is suitable for being applied and popularized on a large scale.