The utility model discloses a gas protection electric loop is thought highly of to vary voltage, including establishing circuit breaker QF2, the QF1 on elementary return circuit of transformer coil and secondary loop, circuit breaker QF1, QF2 are connected to auxiliary relay KOM respectively, and auxiliary relay KOM is connected to signal relay KS through connection piece XE or change over switch, and signal relay KS is connected to buchholz relay KG, signal relay KS and buchholz relay KG are connected to the controller respectively. The device further improves electric relay protection function, guarantees the more secure economic even running of industrial enterprise, thinks highly of gas protection return circuit in the vary voltage and carries out the innovative design, has realized that the transformer is because of the heavy gas tripping off transformer the?normal?power supply of error reporting, impact?systems operation when special?circumstances moves.