Gastrointestinal diseases are a relatively common disease, and the advent of endoscopic technology is important for the early detection and treatment of this disease. In order to adapt to current medical conditions, endoscopic robots that can move autonomously are known to be the trend of development. Most of the current capsule endoscopic robots use simultaneous localization and mapping SLAM technology to localize the capsule robot and create a map of the intestinal tract. his paper summarizes the classification of capsule endoscopy robots by referring to several articles on capsule endoscopy robots. Their working methods, advantages and disadvantages are analyzed by comparing the various types of capsule endoscopy robots horizontally. This paper also analyses the application of SLAM technology to capsule endoscopy robots. The future development of capsule endoscopy robot is prospected by combining the mainstream SLAM software and hardware technologies today. This provides the development direction for the future development of capsule endoscopy robot.