The utility model relates to a caliper compasses, comprising a steel-needle compasses leg, a perforated groove on the steel-needle compasses, a dispiro hole vertical set on the closed side of the groove with a handle and a hand screw, an extension terminal set on another closed side of the groove relative to the handle part perpendicular to another closed side of the groove and in the same axle with the handle, a steel needle on the end of the extension terminal in the same axle with the extension terminal and connected with the extension terminal; a lead core compasses leg, composed of a set of rulers in the groove on the steel-needle compasses, a hand-grasping part formed on one end of the ruler with larger circumference thickness than the ruler, a stabilizer projected from the ruler perpendicular to the bottom of the hand-grasping part with equal length to the extension terminal of the steel-needle compasses, a groove on the connection edge of the stabilizer terminal and steel-needle compasses leg, a bolt hole at the bottom of the groove and perpendicularly penetrating the groove, a perforation screw on the screw hole, a hand screw sleeved on the external end of the perforation screw, a bolt hole perpendicularly set on the inner terminal of the perforation screw and a lead core sleeved in the bolt hole.