The utility model relates to measuring caliper technical field, and disclose a kind of length precision measuring caliper structure, including measuring rod, measuring rod one end is provided with a number of jaws, measuring rod inside is provided with sliding slot, sliding slot is provided with telescopic rod, measuring rod upper end surface inside is provided with a number of scale lines, telescopic rod upper end surface is provided with the second number of scale lines that a number of scale lines mutually cooperate, telescopic rod front end extends sliding slot and is provided with the second number of jaws.The length precision measuring caliper structure, by being provided with measuring rod and telescopic rod, pull out the second number of jaws, telescopic rod extends outward, so that a number of jaws and the second number of jaws are respectively clamped in the both ends of the measured part, by tightening fastening nut and compressing measuring rod, the position of boss is fixed, so as to effectively play the fixing effect to the position of telescopic rod, it is convenient to further read the numerical value on the second number of scale lines, the length of measuring rod and the extension length of telescopic rod are added, and it is the length of the measured part, easy to operate.