Abstract: Based on the electrochemical reaction mechanism, the generation conditions of AC corrosion in cathodically protected pipeline are analyzed in this article, as well as the effects of electrochemical parameters, physical and chemical parameters related to AC corrosion assessment on the AC corrosion density or AC corrosion rate. Accurate detection data of AC corrosion is the foundation of AC interference assessment and basis of AC corrosion mitigation. Since the stable duration of AC interference is different, and the AC disturbance voltage varies with the seasons, weather, load, cathodic protection current density, more pertinent and new testing devices and equipment are needed for the AC corrosion detection, assessment, mitigation of cathodically protected pipeline.