Abstract: Hard@soft composite carbon can improve the potassium storage performance synergistically by combining the advantage of hard carbon and soft carbon. But the potassium storage mechanism of different composite structure is lack. Here, rhodanine and F127 were used as the precursor of hard carbon, and the volatile matter of coal tar pitch was used as the precursor of soft carbon. Hard carbon, soft/hard hybrid carbon and soft carbon shell@hard carbon core composite were fabricated using co-carbonization and chemical vapor deposition. When used as the anode materials of potassium-ion battery, soft carbon shell@hard carbon core composite possesses high reversible capacity (365 mA·h·g⁻¹ at 0.05 A·g⁻¹), high cyclic stability (80% after 100 cycles), and excellent rate performance (177 mA·h·g⁻¹ at 1 A·g⁻¹). It can be ascribed to the abundance of active sites of hard carbon and the coating of soft carbon on the defect sites at the surface of hard carbon. Moreover, the soft carbon can improve the conductivity of the composite, which can enhance the rate performance of composite anode and release the voltage hysteresis. Benefiting from the synergistic potassium storage, soft carbon shell@hard carbon core composite anode shows much better performance than hard carbon anode.