The invention relates to an insulator series-parallel gap lightning impulse effectiveness and discharge characteristic test method. According to the method, a lift test principle method and a forcing test method are applied through a main processor and image acquisition; lightning impulse 50% discharge voltage, a lightning impulse volt-second characteristic and the effectiveness and invalidity of an insulator series-parallel gap can be simultaneously acquired; and the effective application of a parallel gap in the lightning protection of a transmission line is enhanced.