The utility model relates to a sectional type calliper for measuring insulator arris inslot footpath. Its characteristics are: including the big arm in a left side and the right side big arm (1), the big arm top in this left side is passed through rivet (4) with big arm (1) the top in the right side and is articulated together, to pass through rivet (4) together articulated on the top of arm in the bottom of this big arm in a left side and the left side, to pass through rivet (4) together articulated on the top of bottom and the left forearm of arm in this left side, and to pass through rivet (4) together articulated on the top of arm (2) in the bottom of this right side big arm (1) and the right side, the bottom of arm in this right side (2) is passed through rivet (4) with the top of right forearm (3) and is articulated together. Through identification on probation, adopt the utility model discloses a behind the sectional type calliper, the diameter of can be directly accurate measurement insulator, especially large -tonnage bell jar type insulator lower surface arris inslot to be convenient for estimate the insulator surface area.