The invention provides a high-performance rare earth barium copper oxide high-temperature superconducting film precursor solution and a preparation method thereof. The precursor solution is prepared from solute and a solvent; the solute is prepared from rare earth acetate, barium acetate and copper acetate in the cationic atom ratio of (0.5-2.5):(1.5-2.5):(2.5-3.5); the cationic concentration in the precursor solution is 0.5-3 mol/L. The method comprises the steps that the solute and the solvent are mixed in proportion, and under the airtight condition, heating, stirring and cooling are conducted. Compared with the prior art, the precursor precursor and the preparation method have the advantages that precursor solution synthetic raw material is friendly to environment, toxic and harmful substances do not exist, and the synthetic process is simple and controllable; the precursor solution ingredients, concentrations, rheological property and the like are precise and adjustable, and requirements of the coating technologies such as subsequent spin-coating or dip-coating can be met; the precursor solution is adopted for preparing a high-performance rare earth barium copper oxide, in theheat treatment process, no toxic or harmful intermediate product exists, and high speed growth of a superconducting film can be achieved.