This study develops a spectral analysis method to provide a convenient method for quantitatively analyzing flicker of electric light sources for mass basic quality inspectors. This method only requires the use of transient spectral data of electric light sources measured by a common spectrometer within a certain period of time, instead of using light source stroboscope and digital oscilloscope. By the means of high-quality fitting of the spectral luminous efficiency function of photopic vision, calculation of relative light flux, and eight-step Fourier fitting, the scintillation percentage, stroboscopic depth, and stroboscopic frequency of incandescent, LED filament, and iodine tungsten lamps are calculated and analyzed, and the test results are compared with data measured by an LFA-2000 light source stroboscope. The results show that the average relative errors of scintillation percentage, stroboscopic depth, and stroboscopic frequency for these three types of electric light sources calculated by this method are 4.93%, 4.89%, and 10.17%, respectively, and the corresponding maximum relative errors are 8.31%, 7.95%, and 14.22%, respectively. The method is proven to be correct, feasible and accurate when the stroboscopic frequency of the measured light source is less than 200 Hz. This method can provide references for the development of related instruments and equipment, as well as the research and quality inspection of artificial lighting equipment.