Iron phosphide (FeP) is a promising anode material for sodium-ion batteries due to its high theoretical capacity, moderate operating potential and nature abundance. However, its mechanical instability during sodiation/desodiation process frustrates the electrochemical performance. Here we present an elaborated structure that effectively addresses the mechanical stability issues of FeP anodes. Ultrafine FeP nanodots uniformly distribute inside the nitrogen doped carbon nanosheets (NC), which connect each other to construct open-framework structure FeP@NC with abundant connected mesopores and high specific surface area. The well-engineered structure not only ensures the structural integrity of FeP@NC material during repeated cycles, but also guarantees the fast electrode reaction kinetics. As SIB anodes, the prepared FeP@NC delivers excellent rate capability and extraordinary long-term cycling performance. A stable specific capacity of 374 mAh g⁻¹ is achieved at current density of 0.5 A g⁻¹ for 2000 cycles.