Abstract: In order to conduct constant and real-time monitoring on local pipeline corrosion, a fiber bragg grating (FBG) hoop strain sensor was developed, and its principle on local pipeline corrosion monitoring was introduced in this paper. Local corrosion of pipelines is monitored by measuring the average loop strain of pipelines based on the FBG hoop strain sensor. This sensor is installed at the outer wall of steel pipelines whose wall thickness is locally reduced at different degrees to measure the average loop strain of each section, and then simulation experiments are performed on local corrosion. The average loop strain of the sections with different corrosion degrees is calculated at the same pressure based on the theory of material mechanics and then simulated by the finite element software. Results show that the FBG hoop strain sensor can be used to reflect the local corrosion degree of pipelines by monitoring the variation of average loop strain of pipelines. This method is surely promising in monitoring local corrosion of pipelines.