The utility model relates to a PT resonance damp device of a distribution network, which belongs to the technical field of the control protection. The device comprises a damp reactor (4), inverse parallel controllable silicon (5) and a trigger controller (6), wherein, the damp reactor (4) and the inverse parallel controllable silicon (5) are connected in series to form a damp control main circuit (3) and are connected to the port of a PT secondary side opening triangle winding. The utility model has the advantages that the PT resonance damp device can effectively distinguish the resonance and single-phase grounding failure, accurately actualize the damp control of the resonance, and exactly indicate the occurrence of frequency demultiplication, fundamental frequency and high-frequency ferromagnetic resonance or single-phase grounding failure for the system. The device does not influence the normal operation of the electric fence and the collection of zero-sequence signals of the system, and does not generate ultraharmonics and other interference signals.