The invention belongs to the photoelectric film technology field, and particularly discloses a preparation method of a TiO2-dopted film. <{EN2}>The method comprises the steps of (1) preparing a 100-400 mM TiCl4 aqueous solution while stirring; (2) dissolving metal-doped salt into a dissolved solvent according to an object dope proportion, and adding the mixture to the solution prepared in step (1) after stirring uniformly; (3) putting a substrate into the solution obtained in step (2), and controlling the solution temperature at 70-150 DEG C for 10min-5h; (4) taking out the substrate and cleaning with ethanol and water in order; and (5) controlling the temperature of the cleaned substrate at 100-150 DEG C and annealing for 30min-3h. The resultant on the substrate is the TiO2-dopted film. <{EN3}>The compact TiO2-dopted film can be obtained directly from the solution; the whole process can be carried out at a low temperature in normal atmosphere; the film can be formed on the substrate at one time; finally, the invention provides a TiO2 film that is dopted with different elements at a low temperature; and the performance of a perovskite solar cell is greatly improved.