A YBCO superconductive composite thin film preparation method is disclosed and comprises the following steps: organic salt doped with an element which is one of manganese, lanthanum, molybdenum and tungsten is added in a precursor solution containing trifluoroacetic acid yttrium, trifluoroacetic acid barium and cupric acetate cupric acetate; via control over concentration of metal ions and trifluoroacetic acid, temperature and atmosphere can be adjusted during heat treatment processes, and a YBCO superconductive composite thin film containing high-melting point high-melting point oxide nanometer particles is manufactured; magnetic flux pinning effects of the high-melting point oxide nanometer particles are used for improving critical current density of the YBCO thin film.