Abstract: The present utility model provides a compulsory triggered spark gap system with double gaps in series, said spark gap system includes two self-discharge main gaps in series G1, G2 and a gap trigger system, the two ends of the spark gap system are respectively connected with the high voltage end and low voltage end; said gap trigger system and said self-discharge main gaps is parallel. The present utility model is suitable for not only series compensation device, also the series resonant type fault current limiter and fast bypass capacitors, it reduces the trigger discharge voltage value, improves the performance of protection coordination, and the trigger discharge stability and reliability.