Core drilling machine capable of accurately positioning length of core sample

The utility model provides a core drilling machine capable of accurately positioning the length of a core sample, which comprises two graduated scales, two buckles, a core drilling machine cross rod,a base and a drilling machine head, the core drilling machine cross rod is vertically arranged on the base, the graduated scales are arranged on the side wall of the core drilling machine cross rod, and the two buckles are movably arranged on the graduated scales. Wherein the two buckles can slide up and down along the graduated scale to play a role in marking, and the drilling machine head is movably installed on the cross rod of the core drilling machine through a guide sleeve mechanism and can move up and down along the cross rod of the core drilling machine. The core drilling machine is simple in structure and convenient to operate, by additionally arranging the graduated scale and the buckle on the core drilling machine, workers are informed of the requirements for the buckle positionand the core sample contr