Abstract: With the application and promotion of magnetic coupling wireless power transfer (WPT) systems, the research on foreign object detection technology has attracted more and more attention. This paper reviewed the current research status of foreign object detection technology in magnetic coupling WPT systems. Firstly, the main teams researching foreign object detection technology were introduced. The definitions of the foreign object and the foreign object detection technology in various kinds of literature were summarized. The main research results for the influence mechanism, influence law, modeling methods, and foreign object detection methods were focused analyzed. The advantages, disadvantages and application scope of several commonly used foreign object detection methods were given. Finally, the future research directions of foreign object detection technology were discussed.