A porous carbon with multiple pore size distribution was synthesized, and regarded as a carrier to obtain the sulfur/carbon (S/C) composite via a gas-phase loading method. We proposed this novel gas-phase loading method by using a specially designed fluid-bed reactor to encapsulate and sequester gas-phase sulfur molecules into the porous carbon in current study. The nitrogen Brunauer-Emmett-Teller (BET), scanning electron microscopy (SEM) and X-ray powder diffraction (XRD) characterizations were investigated on both the porous carbon and the sulfur/carbon composite. The results show that the gas-phase loading method contributes to the combination of sulfur molecules and matrix porous carbon. Furthermore, the sulfur/multiple pore size distribution carbon composite based on the gas-phase loading method demonstrate an excellent electrochemical property. The initial specific discharge capacity is 795.0mAh g−1 at 800mAg−1, with a capacity retention of 86.3% after 100 cycles.