Abstract: The present invention relates to dental medical instruments, and specifically discloses an automatic grinding drill device for oral caries, including a mounting frame. Two retainers are arranged on the mounting frame, the bottom of the mounting frame is connected with a support plate through drive assemblies, a drill bit assembly is arranged at the bottom of the support plate, and a visual recognition module is also arranged on the support plate. The present invention has the advantage that the retainers keep a real-time relative static state with teeth of a patient during use, needing no frequent correction, so that operation steps are simplified.