Polyvinyl chloride (PVC), the third most produced polymer globally, is fundamentally constructed from vinyl chloride, which is primarily synthesized via the catalytic hydrochlorination of acetylene. The development of highly stable mercury-free catalysts, such as Au-based catalysts, is of critical industrial significance for advancing green and sustainable practices within the acetylene hydrochlorination industry. The shift from mercurybased catalysts to noble metal single-atom catalysts doped with p-block (N) heteroatoms has emerged as a leading approach, attracting significant research attention in recent years. Nitrogen (N) doping effectively addresses the core challenges of catalyst deactivation and low atomic utilization efficiency, facilitating the formation of stable ultra-fine metal nanoparticles and even single-atom catalysts, which demonstrate exceptional catalytic performance in acetylene hydrochlorination. Building on this foundation, the latest theoretical and experimental research progress is comprehensively reviewed, with a focus on the properties, performance, and mechanisms of N-regulated acetylene hydrochlorination catalysts. The interplay between catalyst structure, catalytic activity, and stability is examined, and performance descriptors for Ndoped singleatom catalysts are summarized to underscore the critical factors in catalyst design. Finally, the future development trends of N-regulated catalysts are explored. A deeper understanding of the mechanisms underlying performance enhancement and the structure-performance relationship can provide valuable insights for the targeted synthesis of materials, thereby facilitating the practical application of mercury-free catalysts in acetylene hydrochlorination.