Abstract: Behavior and corrosion principle of stray current are analyzed in the paper. It is pointed out that the stray current is a major cause for the corrosion and leakage of long distance oil and gas pipelines. The author presents a basic operation technique and data acquisition of stray current detector and studies the method for detecting the interference of the stray current. The interference data of the stray current around the pipeline are obtained through site inspection and by means of post-processing software. Verification is carried out to the detected data through pipeline excavation, which exposes the hazard of stray current on the pipeline and availability of the detection.