Abstract: The energy crisis impels innovation in energy storage technologies, spurring the development of new energy solutions to improve the living environment of humanity. Aqueous zinc-ion batteries (AZIBs), due to their cost-effectiveness and promising electrochemical performance, have emerged as charming candidates for commercial energy storage applications. However, the practical implementation of MnO-based electrodes remains hindered by challenges such as low electrical conductivity, Mn ion dissolution, and inadequate cycling stability. Herein, we propose a structural and compositional modification strategy through the design of Fe-doped MnO nanoparticles encapsulated within a pyknotic conductive carbon matrix (FeMnO@C), which is synthesized via calcinating the Fe−Mn bimetallic organic framework precursor. The FeMnO@C composite offers rich active sites that enhance the efficiency of storage and conversion reactions, while its pyknotic carbon layer acts as a protective barrier to suppress manganese dissolution. Additionally, the incorporation of iron improves electrical conductivity and accelerates electron transfer kinetics, thereby further boosting the energy storage performance of this battery. The ex-situ characterization and theoretical calculation confirm the multiple energy storage effect involving intercalation/extraction with H+/Zn2+, along with the Fe2+/Fe0 conversion reaction in this system. With the Fe element introduced and carbon cover combined coupling effect, the FeMnO@C electrode could harvest excellent cycling capacity performance of 148.6 mAh g−1 (92.6%) after 1000 cycles at 0.5 A g−1, 106.2 mAh g−1 (80.8%) after 1500 cycles at 1.0 A g−1, and ultralong lifetime 5000 cycles (90.2%) at 2.0 A g−1, as well as excellent rate performance. Based on the rational design of composite structures and a multistep reaction mechanism, this work offers a novel perspective for developing high-performance electrode materials and investigating energy storage mechanisms in AZIBs.