The utility model discloses a device for measuring the impact stiffness, which comprises a main working table top and a falling table top, wherein the main working table top is arranged on a frame, the frame is arranged on a vibration-damping base through a vibration isolator, a support is fixedly arranged on the main working table top, a detected element is arranged on the support, a force sensor is arranged at the top of the detected element, the detected element is connected with a displacement sensor, the falling table top is arranged above the main working table top, a waveform generator is arranged at the bottom of the falling table top, and the waveform generator is positioned over the force sensor. The device adopts the force sensor and the displacement sensor to achieve the impact characteristics experimental study on high-elasticity impact stiffness and the test of impact parameters. Compared with the method in which the impact force and the deformation are calculated through the measured acceleration in the impact stiffness test of the vibration isolator, the impact stiffness measurement using the device is more accurate, visual and convenient.