A method for quantitative analysis of heavy metals in analytical samples comprising cosmetic or food compositions, the method comprising: a step of preparing a blank liquid standard sample that is a nitric acid solution; a step of preparing two or more liquid standard samples having different concentrations by adding lead, arsenic, antimony or cadmium to the nitric acid solution; a step of selecting an interfering element, which has an energy level falling in a detected energy value range of lead, arsenic, antimony or cadmium, from among elements detected by irradiating X-rays to an analytical sample; a deconvolution step of correcting the detected energy peak of lead, arsenic, antimony or cadmium, among energy peaks detected by irradiating X-rays to the liquid standard samples having different concentrations in the step of selecting the interfering element, from a detected energy peak of the overlapping interfering element; a step of irradiating X-rays to each of the prepared liquid standard samples having different concentrations, and then performing the deconvolution step, thereby preparing a standard calibration curve; and a step of irradiating X-rays to the analytical sample to detect an energy peak, and then measuring the concentration of lead, arsenic, antimony or cadmium in the analytical sample based on the detected energy peak value of the analytical sample by the prepared standard calibration curve according to a standard calibration method, wherein the deconvolution step further comprises a step of correcting the absorption effect of the interfering element to remove an energy intensity value corresponding to an energy level range in which the detected energy peak of lead, arsenic, antimony or cadmium overlaps with the energy peak of the selected interfering element, and wherein the step of correcting the absorption effect of the interfering element further comprises a step of correcting the detected energy peak of lead, arsenic, antimony or cadmium by a Lucas-Tooth/Price algorithm. a step of preparing a blank liquid standard sample that is a nitric acid solution; a step of preparing two or more liquid standard samples having different concentrations by adding lead, arsenic, antimony or cadmium to the nitric acid solution; a step of selecting an interfering element, which has an energy level falling in a detected energy value range of lead, arsenic, antimony or cadmium, from among elements detected by irradiating X-rays to an analytical sample; a deconvolution step of correcting the detected energy peak of lead, arsenic, antimony or cadmium, among energy peaks detected by irradiating X-rays to the liquid standard samples having different concentrations in the step of selecting the interfering element, from a detected energy peak of the overlapping interfering element; a step of irradiating X-rays to each of the prepared liquid standard samples having different concentrations, and then performing the deconvolution step, thereby preparing a standard calibration curve; and a step of irradiating X-rays to the analytical sample to detect an energy peak, and then measuring the concentration of lead, arsenic, antimony or cadmium in the analytical sample based on the detected energy peak value of the analytical sample by the prepared standard calibration curve according to a standard calibration method, wherein the deconvolution step further comprises a step of correcting the absorption effect of the interfering element to remove an energy intensity value corresponding to an energy level range in which the detected energy peak of lead, arsenic, antimony or cadmium overlaps with the energy peak of the selected interfering element, and wherein the step of correcting the absorption effect of the interfering element further comprises a step of correcting the detected energy peak of lead, arsenic, antimony or cadmium by a Lucas-Tooth/Price algorithm.