The electromagnetic wave absorption performance (EWAP) can be significantly improved by incorporating a functionalized layered structure that maximally directs electromagnetic waves deeper into cementitious materials. These waves are absorbed by multicomponent absorbers. This study investigates the influence of different absorber contents, specifically, magnetite (3, 6, 10, and 15%) and copper (Cu)-powder (3, 6, and 9%), as well as functionalized layered structure on the EWAP of magnesium phosphate cement (MPC). The results indicate that the functionalized layered structure can effectively improve the EWAP of MPC. By concurrently employing conductive Cu-powder and magnetic loss magnetite absorbers in the absorbing layer, an increase is observed in the EWAP of MPC. Notably, our proposed MPC with a double-layered structure (MPC10–2b) demonstrates optimum EWAP characteristics with a peak reflection loss of −13.8 dB and bandwidnth below −10 dB across 15.5 GHz. Thus, a functionalized layered structure significantly improves the EWAP of cementitious material, satisfying both the optimal impedance matching and microwave dissipation design criteria for electromagnetic absorbing materials.