The shock response of single freedom system was studied based on impact theory. The shear blade of some merchant shearing machine was selected as the object. The static calibration and impact load testing was carried on the object. Based on the impact theory and finite element technology, the feasibility of the testing scheme and the influence of the shock wave shape on the testing accuracy were discussed. The results show that for the shear blade, when the impact load time history is 50ms and the natural frequency is 2848Hz, there only 0.42% difference between the maximum dynamic response and the static calibrated response. So it is practicable to use the static calibrated results to decide the relationship of the impact load and strain.