In realistic scenarios, microwave absorbing structures (MAS) without mechanical designs and electromagnetic optimization is inapplicable, indicating that MAS has to be multifunctional as long as it would be used. Herein, an impact-resistant multilayered metastructure (IRMM) comprised by ultra-high molecular weight polyethylene (UHMWPE) fiber reinforced polymer (UFRP), carbon fiber reinforced polymer (CFRP) and frequency selective surface (FSS) was optimized by evolutionary algorithms for broadband microwave absorption. The −10 dB absorption bandwidth in 2.7–18 GHz was achieved with ballistic limit velocity of 690 m/s and specific energy absorption (SEA) of 23.54 J·m2/kg in the penetration test, showing that the proposed IRMM was serviceable for shrapnel impact defense in explosive environment. The broadband absorbing property was successfully integrated in the highly effective impact-resistant armor.