Potassium‐sulfur (K‐S) battery has attracted attention in large‐scale energy storage system. Small‐molecule/covalent sulfur (SMCS) can help to avoid shuttle effect of polysulfide ions via solid‐solid sulfur conversion. However, content of SMCS is relatively low (≤40%), and solid‐solid reaction cause sluggish kinetics and low discharge potentials. Herein, SMCS was confined in turbo carbon layers with content of ∼74.1 wt% via a C/S co‐deposition process. In the K‐S battery assembled by using as‐fabricated SMCS@C as cathode and KFSI‐EC/DEC as electrolyte, anion‐regulated two‐plateau solid‐state S conversion chemistry and a novel high discharge potential plateau at 2.5‐2.0 V with remarkable reversible capacity of 384 mAh g−1 at 3 A g−1 after 1000 cycles were found. The SMCS@C||K full cell showed energy and power density of 72.8 Wh kg−1 and 873.2 W kg−1, respectively, at 3 A g−1. Mechanism studies reveal that the enlarged carbon layer space enables the diffusion of K+‐FSI‐ ion pairs, and the coulombic attraction between them accelerates their diffusion in SMCS@C. In addition, FSI− regulates sulfur conversion in situ inside the carbon layers along a two‐plateau solid‐state reaction pathway, which lowers the free energy and weakens the S‐S bond of intermediates, leading to faster and more efficient S conversion.This article is protected by copyright. All rights reserved