In order to improve acknowledge on flare system at high sour gas station, conducted is status analysis on flare system in a certain project and it is pointed out that flare system and reliable automatic electric ignition device shall be equipped in the position upstream of sour gas vent outlet so as to vent it to the air after sour gas is burnt. In combination with relative requirements in codes, standards and specifications, discussed are function setting, fire arresting and ignition devices and system safety operation of flare system. Taking a certain concrete project for an example, proposed is an optimum scheme in which vented gas is used as ignition source and full automatic aerial electric ignition system is added in order to ensure safe venting of sour gas at gas station.