A novel Sodium Alginate-Magnesium Silicate carrier (KM) was developed to address the challenges of slow anaerobic granulation and insufficient shock-loading resistance in coking wastewater treatment using an up-flow anaerobic sludge blanket (UASB) reactor. Compared to the control group, the KM reactor increased anaerobic granulation size by 0.6-fold and improved the shock-loading resistance of granular sludge. First, The KM carrier enhanced the secretion of extracellular polymeric substances (EPS) in sludge by 28 %. Additionally, KM carrier-based granular sludge promoted the secretion of adenosine triphosphate (ATP) and humic substances, facilitated the degradation of phenolics and heterocyclic compounds, and stimulated the production of 2(1H)-Quinolone, a key intermediate in quinolone degradation. This process reduced cellular toxicity, enabling rapid post-shock recovery within 9 days. Notably, the enrichment of Methanosaeta in the KM reactor significantly enhanced anaerobic granulation, improving system resilience to shock loads and optimizing treatment efficiency.