Researches on erosion resistance of valves from the perspective of variable stiffness and energy mitigating are rarely to be seen so far. The ballistic protection for body armor usually requires both high strength and high energy mitigation. Based on the above characteristics of the body armor, ballistic protection for body armor is analogous to the valve plug erosion resistance. In this work, we introduce a new energy mitigating body armor inspired valve plug (EMAVP) to improve its anti-erosion performance. The EMAVP has a gradient hierarchical structure in hardness, variable stiffness materials and structures. The authors analyze the variety of stiffness and energy mitigating of the EMAVP. The fluid-structure interaction (FSI) method is used to simulate the erosion performance, the EMAVP and normal valve plug specimens were tested in the comprehensive experimental system of water hydraulic valve and jet erosion facility. Results show that the EMAVP is superior to normal valve plug, with higher energy mitigating and better anti-erosion performance.