The utility model relates to a measuring equipment, more specifically relates to a standard slide caliper rule, divide into switch measuring junction and earthing knife -switch turning arm measuring junction, sets up respectively at the ruler both ends, and its width size all is the maximum size of the technical standard of producer scope, is made by insulating material to form, and the standard slide caliper rule middle part is equipped with the through -hole and can sets up rotary mechanism. The utility model discloses whether can judge on -off brake position directly perceivedly and targetin place, the effect is very obvious. Use this standard slide caliper rule to overcome that personnel's height can't reach, the constrictive influence of unclear, measurement space is seen to the reading.