Digital caliper for measuring diameter of inner groove of inner groove

The utility model relates to the technical field of measuring tools, and discloses a digital caliper for measuring the diameter of an inner groove of an inner groove. The fastening bolt is rotated to be separated from the inner distance measuring claw, then when the inner distance measuring claw slides to a needed position in the containing groove, the fastening bolt is rotated to fix the inner distance measuring claw, the effect that the length of the inner hole diameter measuring claw can be adjusted is achieved, and therefore carrying and storage at ordinary times can be facilitated; deep apertures with different sizes inside and outside can be measured, and the practicability of the digital caliper is improved; the compasses and the rotating rod are driven to slide out of the placing groove by pulling the sliding plate, then one of two faces of an object needing to be measured is attached to the bottom of the sliding plate, the other face of the two faces of the object needing to be measured is attached t