A field experiment was conducted on coastal saline soil with five treatments:conventional fertilization(CK)，organic fertilizer(OF)，bio-organic fertilizer(BF)，biogas residue compost(BRF)，and biochar(B). The study investigated the effects of different organic material amendments on soil organic carbon(SOC)and labile organic carbon fractions. The experiment was established in October 2023，with surface soil samples(0-20 cm)collected in June 2024 to analyze variations in SOC，labile organic carbon fractions，carbon pool management index，key soil physicochemical properties and their correlations. The results showed that organic amendments significantly enhanced SOC content by 11%-83%，compared to CK，B treatment showing the most pronounced improvement(83%). OF，BRF，and B treatments increased easily oxidizable organic carbon by 77.5%，52.5%，and 52.5%，respectively. Both OF and B treatments elevated water-soluble organic carbon by approximately 8%. Carbon pool activity increased by 33.3% and 47.6% under OF and BRF treatments，respectively，but decreased by 38.1% and 19.0% under BF and B treatments. In terms of soil chemical properties，compared with the CK treatment，the OF，BF，BRF，and B treatments increased soil total nitrogen by 47.3%，56.8%，54.6%，and 53.4%，respectively. The soil carbon and nitrogen ratio(C/N) showed no significant changes in the OF and BF treatments，descreased by 1.20 in the BRF treatment，and increased by 0.80 in the B treatment. The soil pH increased by 0.40 in the OF treatment and decreased by 0.32 in the BF treatment. The electrical conductivity(EC)value increased by 79.8% in the BF treatment，while it decreased by 56.5% in the BRF treatment. Correlation analysis revealed that active organic carbon fractions were primarily influenced by soil total nitrogen content and the soil C/N ratio. The application of organic fertilizer and biogas residue compost was most effective on enhancing the carbon pool quality of saline soil，while bio-organic fertilizer showed the best performance in improving carbon pool stability. Notably，biogas residue compost exhibited the most significant effect on promoting salt reduction in saline soil.