The invention discloses an electric energy metering method based on R-V(III) window FFT double-peak interpolation. The method comprises the steps of based on an Rife-Vincent(III) window FFT double-peak-spectrum linear interpolation correction formula, frequency shifting property of FFT and frequency spectrum of a window function Rife-Vincent(III), obtaining a universal amplitude, phase and frequency interpolation correction formula of a signal fundamental wave, a harmonic wave and an interharmonic wave at a highest spectrum line spectrum and a secondary highest spectrum line spectrum at the left side and the right side of the fundamental wave, the harmonic wave and the interharmonic wave; calculating the amplitudes, the phases and the frequency parameters of the fundamental wave, the harmonic wave and the interharmonic wave of the metered voltage signal and the current signal according to the universal amplitude, the phase and the frequency correction formula; and furthermore calculating the electric energy of the fundamental wave, the electric energy of the harmonic wave, the electric energy of the interharmonic wave and the total electric energy. The electric energy metering method has an advantage of relatively high main lobe performance and relatively high side lobe performance.