Abstract: The application effect of corrosion inhibitor was studied and the effective protection time of it was determined in sulfur gas transmission pipeline using corrosion coupon, residual concentration analysis of corrosion inhibitor and hydrogen monitoring technology. The result showed that hydrogen monitoring technology could monitor the corrosion status of sulfur gas transmission pipeline real-time, nondestructively and full phase. The residual concentration analysis of inhibitor and hydrogen monitoring results showed that the effective protection time of corrosion inhibitor could reach more than 1 month.