The invention relates to a thunder impulse response detection system of a AC line tower. The system comprises a grounding device used for connecting with a ground end, a simulation tower on the basis of a single loop straight line tower of an AC line, a single loop tension tower, a common-tower double-loop straight line tower or a common-tower double-loop tension tower, a thunder impulse current generator which is connected between a top end of the simulation tower and the grounding device and is used for providing a thunder impulse current, a current measurer which is connected between the top end of the simulation tower and the thunder impulse current generator and is used for measuring current parameters of the thunder impulse current generated by the thunder impulse current generator, a voltage measurer which is connected between the top end of the simulation tower and the grounding device and is used for measuring voltage parameters of the top end of the simulation tower, wherein the simulation tower stands on the grounding device, a bottom end of the simulation tower contacts the grounding device. The current parameters and the voltage parameters are used for detecting thunder impulse parameters of the single loop straight line tower, the single loop tension tower, the common-tower double-loop straight line tower or the common-tower double-loop tension tower corresponding to the simulation tower.