The invention relates to an automatic measurement device. The automatic measurement device comprises a measurement mechanism, a telescopic mechanism and a fixed frame; the telescopic mechanism comprises a telescopic arm, a first driving device for driving the telescopic arm to move and a connecting plate fixed with the telescopic arm, and the telescopic mechanism is fixed on the fixed frame; the measurement mechanism comprises a movable claw, a fixed claw matched with the movable claw to clamp a material to be measured, a second driving device for driving the movable claw to move in the direction perpendicular to the telescopic direction of the telescopic arm, and a displacement sensor for outputting the distance between the movable claw and the fixed claw and electrical signals; both the fixed claw and the second driving device are fixed on the connecting plate, and the movable claw is matched with the connecting plate in a guiding mode. The automatic measurement device solves the problems of high labor intensity and low measurement efficiency of manual measurement.