In light of the fact that in different environments in human body, the body miniature medical robots have a different drive mechanism, this paper summarizes the overseas and domestic research status of invivo miniature robot including imitation of biological floating, special mechanical mechanism drive, in vitro special field(magnetic field, ultrasonic field) drive, and capsule endoscopy robot class. Besides, it analyzes the problems in motion control, operation safety of the current in vivo robot drive mechanism. Moreover, it discusses the key technology in vivo robot—the size of the miniaturization, multi degree of freedom with agile miniature drive mechanism, accurate and stable agile control system, effective lasting energy supplies, biocompatibility and so on. Furthermore, it elaborates on the application prospect and development direction of in vivo robot in clinical disease diagnosis and body surgery.