Exploration of nanocomposites with exceptional catalytic activities is essential for harnessing the unique advantages of each constituent in the domains of pharmaceutical analysis and electrochemical sensing. In this regard, we illustrated the synthesis of iron oxide/N-doped reduced graphene oxide (Fe2O3/N-rGO) nanocomposites through a one-step thermal treatment of iron phthalocyanine (FePc), melamine, and graphene oxide for electrochemical sensing. The large specific surface area and good conductivity of N-rGO can efficiently capture rutin molecules and accelerate electron transport, thereby improving the electrochemical performance. Moreover, the Fe2O3 nanoparticles with distinct electronic characteristics significantly enhanced the detection sensitivity of the constructed electrochemical platform. Because of the outstanding electrical conductivity, an extensive surface area, and synergistic catalysis, Fe2O3/N-rGO was employed as an advanced electrode modifier to build an electrochemical sensing platform for rutin detection. Significantly, the manufactured sensor showed a broad detection range from 7 nM to 150 μM and a high sensitivity of 5632 μA mM-1. Furthermore, the fabricated sensor showed desirable results in terms of stability, selectivity, and practical application. This work presents a facile method to prepare Fe2O3/N-rGO and supplies a valuable example for building metal oxide/graphene nanocomposites for electrochemical analysis.