Abstract: This study investigated the spoilage microbial characteristics and quality deterioration patterns of Ningxiang hindleg pork during chilled storage (4 ℃, 0~8 days). Comprehensive analyses were conducted on pH, color, drip loss, protein/lipid oxidation, total viable count (TVC), total volatile basic nitrogen (TVB-N), malondialdehyde (MDA), and biogenic amines. Microbial community dynamics were assessed via Illumina MiSeq sequencing, while volatile compounds were profiled using SPME-GC-MS. Orthogonal partial least squares-discriminant analysis (OPLS-DA) and variable importance in projection (VIP) identified differential volatiles, with key spoilage odorants determined by relative odor activity values (ROAV). Results indicated that pH exhibited a biphasic trend, initially decreasing from 5.92 (Day 0) to 5.79 (Day 2), then rising to 6.34 (Day 8) (P<0.05). Drip loss increased significantly from 1.60%±0.49% to 9.25%±0.22% (P<0.05). The maximum color difference (ΔE=9.40±0.86) occurred at Day 4. Protein/lipid oxidation intensified, evidenced by elevated MDA and carbonyl content, while total thiols declined markedly by Day 6 (P<0.05). TVB-N accumulation followed a sigmoidal pattern, surpassing the regulatory threshold (15.73 mg/100 g) by Day 8. Biogenic amines (putrescine, tyramine, cadaverine) increased progressively, with the biogenic amine index (BAI) indicating spoilage (146.48±0.39 mg/kg) by Day 6. TVC exceeded acceptable limits (7.11 lg CFU/g) by Day 4. Microbial richness (Chao1/ACE indices) surged at Day 4 (P<0.05), with Firmicutes and Proteobacteria dominating spoilage microbiota. Spoilage correlated strongly with Enterobacter, Myroides, and Brochothrix enrichment. GC-MS identified 86 volatiles. OPLS-DA revealed distinct clustering by storage time. Seven VIP-selected compounds (VIP>1.5) differentiated spoilage stages, notably 3-methylthiobutyric acid S-methyl ester and 2-methylpentanoic acid methyl ester (ROAV>1, Days 6~8), imparting putrid odors (fermented tomato/mushroom and tropical fruit notes). Correlation analysis revealed that Acinetobacter bereziniae (LMG_1003__CIP_70.12), Serratia spp., Raoultella spp., Acinetobacter guillouiae, and Citrobacter spp. were significantly positively correlated with the key spoilage odor compounds 2-methylpentanoic acid methyl ester (tropical fruit aroma) and 3-methylthiobutyric acid S-methyl ester (sharp dairy, fermented tomato, and mushroom flavors). In addition, quality indicators such as TVB-N, carbonyl content, cadaverine, and tyramine were significantly positively correlated with these key spoilage odor compounds. This study systematically revealed the mechanisms of quality deterioration of chilled Ningxiang hindleg pork during refrigeration and its relationship with microbial communities and volatile metabolites, providing an important theoretical basis for the preservation and quality control of chilled meat.