Lithium-sulfur (Li-S) batteries have the theoretical energy density up to 2600 Wh/kg, but its commercialization is limited by poor cyclic performance, low coulombic efficiency and high material cost. In this work, the polar cross-linked polystyrene/sulfur (PCP/S) composite with a sulfur content of 58 wt% is firstly synthesized as the cathodes for Li-S batteries, in which these polar cross-linked polystyrene agents effectively adsorb polysulfides with a large specific surface area and various functional groups, resulting in an enhancement of the cycle performance and coulombic efficiency for Li-S batteries. The first specific discharge capacity of the PCP/S cathode is 1309.7 mAh g−1 at 0.2 C, which can remain as high as 659.7 mAh g−1 after 400 cycles with a low capacity decay of 0.124% per cycle.