A positioning device for dental drilling comprises a base and a positioning block. The base comprises an outer wall, an inner wall, a guide groove and two extension portions. The inner wall is opposite to the outer wall the guide groove is surrounded by the inner wall two extension portions respectively extend from two sides of the outer wall and the inner wall, an axial direction of each of the extension portions is parallel to an axial direction of the base, and a distance between the extension portions is smaller than a distance between two ends of the inner wall so that the drill will not deviate from guide groove. The positioning block protrudes from the outer wall of the base. The positioning device can be firmly embedded in the surgical guide due to the positioning block.
