The polysulfide shuttle effect and slow sulfur redox kinetics impede the practical use of lithium-sulfur batteries, whereas single-component catalysts often do not achieve the equilibrium between strong adsorption, high catalytic activity, and rapid charge transport. Conductive Mo spheres were in situ synthesized within the two-dimensional interlayers of MoB MBene by using the high-temperature aggregation properties of Mo. The resultant sheet-sphere heterostructure improves interlayer stability via a self-pillaring action and reveals deep catalytic sites in MoB MBene. More importantly, the incorporation of metallic Mo induces pronounced interfacial electronic coupling and charge redistribution at the Mo/MoB interface, thereby regulating the local electronic structure, facilitating interfacial electron transport, and promoting the adsorption and catalytic conversion of lithium polysulfides. The Mo-MoB based sulfur cathode provides a capacity of 1001.1 mAh g^-1 at 0.2 C and maintains 581.7 mAh g^-1 after 300 cycles. At 1 C, it retains 424.4 mAh g^-1 after 1000 cycles with a minimal decay rate of 0.041% per cycle. This study presents a novel approach for the development of high-performance Li-S batteries catalysts and the enhancement of MBene applications.