The invention relates to a real-time three-phase electrical network impedance detection method on the asymmetric electrical network condition and is applicable to rapid electrical network impedance detection in solar energy grid-connection generation. The method comprises steps that, three-phase symmetric harmonic wave currents in 175Hz and 325Hz non-characteristic frequencies are injected into an electrical network; the two non-characteristic frequency harmonic wave current components in the currents are separated; the two non-characteristic frequency harmonic wave voltage components in electrical network voltages are separated; phases of the two non-characteristic frequency harmonic wave currents are respectively acquired; effective values of the two non-characteristic frequency harmonic wave voltages are respectively resolved; included angles of the two non-characteristic frequency harmonic wave voltages and the two non-characteristic frequency harmonic wave currents are respectively calculated; each-phase electrical network impedance is respectively calculated according to the acquired voltage, the acquired current and angle information. The real-time three-phase electrical network impedance detection method has advantages of rapid calculation speed and small computational complexity and is applicable to electrical network impedance detection on the condition of asymmetric electrical network voltages and asymmetric electrical network impedances.