High-entropy oxides (HEOs) with five or more metal components in a single oxide phase, hold attractive potential to enhance the lithium polysulfides (LiPSs) adsorption-catalysis ability in Li-S batteries due to the noteworthy synergistic effect of the multiple metal sites. Herein, we have synthesized a RuO2-based HEO, i.e. (RuIrFeCoNi)O2 via a simple molten salt method for Li-S batteries. Our results prove that the introduction of multiple metal components endows HEO with moderate adsorption of LiPSs and promising bidirectional catalysis on the liquid-solid conversion between soluble LiPSs and insoluble Li2S. Particularly, compared with the quaternary (RuFeCoNi)O2 catalyst, the inferior kinetics enhancement of the LiPSs generation, but the superior promotion of Li2S deposition for HEO greatly favors the inhibition of shuttle effect. Such an asymmetric catalysis behavior induces remarkable electrochemical performance of Li-S batteries assembled with HEO-modified separator. High specific capacities of 1641.1 mAh g-1 at 0.1 C and 812.5 mAh g-1 at 2 C are achieved. Remarkably, superior cycle stability is realized with a low capacity decay rate of only 0.060% per cycle within 1000 cycles at 1 C rate. This study unveils the catalytic mechanism of HEO in promoting polysulfide conversion and offers a robust foundation for designing efficient catalysts for Li-S batteries.