Abstract: To predict and analyze the future corrosion rate of wet gas pipeline(^# 20 steel), the corrosion detection on accumulated corrosion rate of pipe metal in the extreme condition is made on 10 typical gas productivity gas pipelines. The results show that the gas transmission throughput and water/gas ratio are the leading factors to form corrosion. It is pointed out that the corrosion rate is developing with the growth of gas transmission throughput and water/gas ratio, and when the two is closed to each other, the corrosion rate is developing with the growth of H₂S content. The H₂S near the welds of base metal will result in HIC or embrittlement for the gas pipeline, and with the growth of H₂S content in the gas, the trend of HIC will tend to be obvious. In addition, the corrosion rate in bending pipe will be high due to the erosion and corrosion.