Abstract: The high-sulfur gas gathering pipelines in Puguang Gasfield are probably corroded. Intelligent pigging detectionis conducted before and after the commissioning in order to fully understand the pipeline status. Ten external metal losspoints are found before commissioning, and nine external defect points and seven internal ones are found after one year ofcommissioning. The excavation and test show that the external metal loss is caused by construction or operation, while theinternal metal loss is caused by the gas-liquid interface corrosion. The probability statistics method is applied to evaluatethe reliability of the pipeline, and the residual intensity theory is adopted to evaluate the safety of the pipeline. The resultsindicate that the defect points have no remarkable influence on the pipeline safety. The pipeline has a high reliability.