The invention relates to a clamping sheet exposing value measuring device of a front clamping type jack and particularly relates to a measuring tool for measuring a clamping sheet exposing amount variable quantity of the front clamping type jack in a stretching-drawing process. The clamping sheet exposing value measuring device of the front clamping type jack comprises a steel plate ruler and is characterized in that the steel plate ruler is provided with a thick steel wire penetrating into the front clamping type jack in parallel through a fixing part; the top of the thick steel wire penetrating into the front clamping type jack is provided with a high-strength magnet for fixing the thick steel wire and a clamping sheet measuring indicator which moves along with a clamping sheet; the measuring indicator is connected with a reading indication indicator capable of sliding on the steel plate ruler through a fine steel wire; and the lower end of the reading indication indicator points at the back side of the clamping sheet measuring indicator and is provided with a spring device which is used for keeping the clamping sheet measuring indicator and the clamping sheet to be tightly contacted. The adoption of the equipment has the beneficial effects that a worker can directly read out readings of each stretching-drawing control point and real-time monitoring is realized.