The invention discloses a method for measuring composition of ReBCO high-temperature superconducting films. The method includes steps of preparing samples; setting measurement parameters; inputting measurement solution; measuring the samples and analyzing measurement results. The method has the advantages that the method for reliably precisely measuring the composition of the high-temperature superconducting metal oxide films is created, application of microwave plasma atomic emission spectrometers to measuring the composition of the high-temperature superconducting films is developed at first, influence of the composition of the high-temperature superconducting films on superconducting currents can be determined, and relations between proportions of metal ions in MOCVD (metal organic chemical vapor deposition) chemical source solution and the composition of the superconducting films can be established.