Abstract: A theoretical study was conducted on the design method of simulated loads based on plane charge explosion technique. Based on the assumptions of one-dimensional strain and quasi-static cavity pressure, combined with the rigid-perfectly plastic-locking model and the theory of plastic wave propagation, a theoretical model of dynamic response for planar charge explosion experiments was established. An analytical solution for load prediction considering overburden compression and overall movement was proposed, and the effects of various parameters, including the mechanical properties of overburden, overburden thicknesses, and cavity heights, on the characteristics of the simulated load were analyzed. The results show that under different charge densities, overburden thicknesses, and overburden types, the theoretical predictions are in good agreement with the numerical results. Thus, the proposed model offers a reliable theoretical framework for the load design of planar charge simulation experiments. The characteristics of the simulated load are closely related to the mechanical properties of overburden, overburden thicknesses and initial cavity heights, which affect the characteristics at the early loading stage, the late loading stage and the whole loading process, respectively. The more compressible the overburden material, the thicker the overburden, or the smaller the initial cavity height, the faster the simulated pressure time-history curve attenuates. In load design, a small initial cavity height should be prioritized to reduce experimental cost and improve experimental reliability.