<p>Biomass hard carbon materials are considered as one of the most promising anode materials for sodium ion batteries due to their cost-effectiveness and low-voltage plateau capability. In this work, phosphorus-doped sisal fiber carbon (PSFC) anode material for sodium ion batteries with rich mesopores and micropores and high capacity retention was prepared by a one-step method using sisal fiber (SF) as the raw material. The P doping greatly improved the microstructure and the electrochemical performance of SFC. The specific capacity of PSFC was as high as 335.575 mAh g⁻¹ for the first turn charge at a current density of 0.05 A g⁻¹, and still maintained at 292.55&#xa0;mAh g⁻¹ after 500 cycles, with capacity retention rate as high as 87.1%. The first cycle efficiency is even improved from 19.65 to 45.55% for SFC. This work provides a simple and rapid strategy for improving the electrochemical performance of biomass hard carbon anode materials, with great potential for application.</p>