The porous Fe₂O₃@Fe₃C@C composite was synthesized by a simple two-step thermal treatment and its structure, morphology, lithium ion storage performance and diffusion kinetics were discussed. Benefitting from the high theoretical capacity of Fe₂O₃ and fast kinetics of Fe₃C, the Fe₂O₃@Fe₃C@C composite exhibits a stable cycling capacity of 800.3 mAh g⁻¹ after 100 cycles at 0.1 A g⁻¹ with superior rate capability. The CV and in-situ EIS analysis results reveal that the Fe₂O₃@Fe₃C@C composite has reversible redox reaction, stable solid electrolyte interphase films and low charge transfer resistance during the discharging and charging process. In addition, the lithium ion diffusion coefficients of the Fe₂O₃@Fe₃C@C composite at different voltage states are investigated by GITT measurement. This work can provide an effective strategy for synthesis of metal oxide@metal carbide composite for lithium-ion batteries.