Porous nanoreactors demonstrate immense potential for applications in heterogeneous catalysis due to their excellent mass‐transfer performance and stability. The design of a simple, universal strategy for fabricating nanoreactor catalysts is of significance for organic transformation. In this study, a nanoreactor with a hierarchical mesoporous yolk‐shell structure was successfully prepared by the high‐temperature carbonization of a ZIF‐67@polymer composite. The core of the resultant Co@ZDC@mC material comprised Co NPs anchored in the ZIF‐67‐derived carbon framework, while the shell comprised resin‐polymer‐derived mesoporous carbon. The as‐obtained Co@ZDC@mC‐700 catalyst enriched reactants, efficiently catalyzed the reaction in the core, and permitted the desorption of the product from the nanoreactor. In the catalytic reduction of nitrobenzene with N2H4⋅H2O, Co@ZDC@mC‐700 exhibited superior catalytic efficiency (TOF=1136.3 h−1). In addition, Co@ZDC@mC‐700 exhibited excellent performance for the catalytic reduction of various functionalized nitroarenes, as well as good reusability and recyclability. Hence, a simple, useful approach for fabricating a metal‐organic‐framework‐derived non‐noble metal‐based yolk‐shell nanoreactor for effective catalytic transformation is proposed.