The calcium looping technology employing CaO‐based sorbents is pivotal for capturing CO2 from flue gas. However, the intrinsic low thermodynamic stability of CaO‐based sorbents and the requisite molding step induce severe sintering issues, diminishing their cyclic stability. Herein, a high‐entropy fluorite oxide (HEFO) inert stabilizer premised on entropy stabilization and synergistic effect strategies is introduced. HEFO‐modified, CaO‐based sorbent pellets are synthesized via a rapid cigarette butt‐assisted combustion process (15 min) combined with the graphite molding method. Post‐multiple cycles, their CO2 capture capacity reaches 0.373 g g−1, which is 2.6‐fold superior to that of pure CaO, demonstrating markedly enhanced anti‐sintering properties. First, the subtle morphological and crystallographic modifications suggest that the inherent entropy stability of HEFO imparts robust thermal resistance. Concurrently, the disordered structure of single‐phase HEFO exhibits a high affinity for CaO, resulting in an interface binding energy of −1.83 eV, in sharp contrast to the −0.112 eV of pure CaO, thereby restricting CaO migration. Additionally, the multi‐element synergistic effect of HEFO reduces the energy barrier by 0.15 eV, leading to a 40% and 140% increase in carbonation and calcination rates, respectively. This work presents highly efficient and rapidly synthesized CaO‐based sorbent pellets, showcasing promising potential for industrial application.