Tailoring surface composition and structures of catalysts affects their catalytic performance in hydrogen evolution reaction owing to the geometric and electronic effects. Herein, Ru nanoparticles embedded in 2D N-doped carbon nanosheets decorated with 2D Fe₃O₄–Fe₃C heterostructures (Ru/Fe₃O₄–Fe₃C/NC) are fabricated via pyrolysis of the mixture containing 2D-Fe₂O₃ nanosheets, dopamine hydrochloride, RuCl₃·xH₂O, and melamine. Interestingly, the good hydrogen evolution behavior is achieved on Ru/Fe₃O₄–Fe₃C/NC with the high reactivity and stability. Ru/Fe₃O₄–Fe₃C/NC offers an overpotential of 141 mV to realize the current density of 10 mA/cm² in 0.5 mol/L (M) H₂SO₄ electrolyte. As for 1 M KOH, Ru/Fe₃O₄–Fe₃C/NC promotes hydrogen evolution reactivity with 148 mV to achieve 10 mA/cm². The current density slightly degrades after continuous I-t tests, verifying the good stability for Ru/Fe₃O₄–Fe₃C/NC. The high reactivity might stem from high dispersion of Ru nanoparticles, enhanced conductivity due to doping N into carbon nanosheets, and heterointerfaces between Fe–O and Fe–C.