In this paper, the sensing block method proposed by Tanimura etc. which would be used to measure the dynamic force, was discussed numerically by LS-DYNA finite element. The influence of reflected stress waves from the base block were analyzed when the sensing projection was in a larger size range. The result shows that it can’t measure the dynamic load accurately with increasing the size of sensing projection. Furthermore, an improved method was developed and discussed with its application in the large-scale device for measurement of the dynamic load.