The utility model discloses an activated measuring device of concrete alkali. Including bottom plate (1), the bottom plate top surface is equipped with the taking of two parallel scale (2) and a set of perpendicular to bottom plate top surface scale cylinder (5), article two, be equipped with slide damper (3) slide damper and scale sliding connection between the parallel scale to through the bolt fastening, a set of taking is equipped with bow-shaped splint (four to six-tenehs) on the scale cylinder, and the bow-shaped splint bottom is equipped with sleeve (9), is equipped with the jackscrew on the sleeve, the sleeve with take scale cylinder sliding connection, the bow-shaped splint both ends are equipped with probe (8) and amesdial (7) respectively. Its mode is through slide damper adjustment horizontal position, through the high position of bow-shaped splint adjustment to realize the measurement of different dimensions's concrete sample. The utility model discloses a device does not receive the restriction of test piece size, and can make through the position of adjustment slide damper and bow-shaped splint the amesdial with pop one's head in be located the concrete sample both ends the center in order to ensure accuracy of measurement.