The self-locking refined quantitative osteotome includes one osteotome with screw hole, one osteotome sheath with slot to coat three sides of the osteotome, one locking screw, and one regulating screw connected between the stretched arm of the osteotome and the stretched arm of the osteotome sheath. The osteotome has scale in the position to combine with the osteotome sheath. The osteotome is provided in different sizes and its feeding depth may be controlled precisely, so that the present invention can control the bone taking amount and range quantitatively.