Online maintenance method suitable for emergency cut-off valve of high-sulfur-content gas field

The invention relates to an on-line maintenance method suitable for an emergency cut-off valve of a high sulfur gas field. The method comprises the steps that S1, signals of an ESDV are overridden in an SIS system, a bypass valve of an ESDV executing mechanism is set to be in a local control state, the executing mechanism is pressurized, it is ensured that the hydraulic pressure of the executing mechanism is sufficient, and the valve is in a forced shielding state; s2, an ESDV instrument wind source is cut off, an execution mechanism air supply pipeline is subjected to pressure relief, an electromagnetic valve is powered off, an instrument wind connection pipeline is dismantled, a signal cable is dismantled, and an execution mechanism connection bolt is dismantled; s3, hydraulic jacks are installed at the front end and the rear end of the executing mechanism correspondingly, the executing mechanism is pushed, a ball valve rod is separated from a coupling sleeve of the executing mechanism, and the executing me