Abstract: In order to monitor the corrosion state of the submarine pipeline, predict the corrosion rate of the pipeline and evaluate the change of pipeline strength, through the detection and analysis of corrosion products of submarine pipeline, it is pointed out that gas corrosion occurs inside the sea pipe. Through the statistical analysis of corrosion defects, the remaining wall thickness and the corrosion depth range of submarine pipeline are obtained by means of magnetic particle detection of weld seam, and the corrosion prediction model of submarine pipeline is established by using OLGA7.1 software. The corrosion rate of submarine pipeline is calculated and analyzed.The results show that the corrosion of submarine pipelines is easy to occur after scaling. The corrosion depth of submarine pipelines is 0~6.9 mm, and the corrosion rate is 0.015~0.022 mm/a. The corrosion rate decreases in the rising section of pipeline elevation and increases in the falling section of pipeline elevation.It provides basis for monitoring and maintenance of submarine pipeline.