Porous polymers have attracted tremendous interest in lithium-sulfur batteries due to the combination of good physical confinement and chemical immobilization to suppress the polysulfide shuttle. Currently, the development of facile and effective methods for fabrication of porous polymers with hierarchical porous structures, strong polar species, and efficient charge-transfer pathways is significant yet challenging, which is crucial for high-performance sulfur cathodes. Herein, for the first time, we present the successful development of a novel class of advanced hierarchical porous polymer nanosheets (AHPPNs) based on a union of surface-initiated atom transfer radical polymerization and a cross-linking-induced coassembly strategy. Due to their well-defined nanoarchitectures, AHPPNs are capable of providing a commendable shuttle-suppressing shield for polysulfides via strong chemisorption, hierarchical porous structures for immobilizing sulfur and relieving volume change, and shortened pathways for ions and electrons. Benefiting from these synergistic effects, the lithium-sulfur batteries assembled with S@AHPPNs cathodes exhibit greatly enhanced rate performance and long stable cycle capability.