The paper presents the methodology for determination the numerical prognosis of the dynamic response of the rectangular steel slab subjected to an explosive load, aimed at thorough preparation of experimental tests. In the presented work, in order to fully describe the parameters of the shock wave impact on the steel slab, an appropriate combination of formulas known in the literature was used. In order to describe the dynamic behavior of the rectangular steel slab, the resources of the ABAQUS computing software were used. The Johnson-Cook constitutive model was used to describe the dynamic behavior of the structural material. An explicit procedure has been used to solve the equations of motion for the slab. The parameters of the shock wave from the explosion of the TNT charge with the assumed mass and the distance of its location from the slab were determined. As a result of the numerical analysis, the results of changes in displacement and acceleration in time were presented, indicating the nature of the very intense and fast-varying dynamic behavior of the slab. Conclusions were also formulated regarding the requirements for the selection of parameters of the sensors recording both the function of real explosion pressure in time and the function of acceleration in time of the slab model during experimental tests.