Forest succession represents a fundamental ecological process that profoundly alters soil organic carbon (SOC) and soil moisture dynamics through complex biogeochemical and hydrological interactions. This comprehensive study examines the coupled dynamics of SOC accumulation and soil moisture regulation across a 150-year forest succession chronosequence in temperate deciduous forests. We monitored 24 forest stands representing six successional stages from early pioneer (5-15 years) to old-growth conditions (>120 years), measuring SOC stocks, soil moisture content, hydraulic properties, and microclimatic variables at multiple soil depths (0-10, 10-30, 30-60, and 60-100 cm) over a five-year period. Results demonstrate strong positive correlations between SOC accumulation and soil water retention capacity (r = 0.84, P < 0.001), with SOC increasing from 42.3 ± 8.7 Mg ha⁻¹ in early succession to 127.6 ± 23.4 Mg ha⁻¹ in old-growth stands. Soil moisture content showed corresponding increases from 18.2 ± 4.1% to 31.7 ± 6.8% volumetric water content during drought periods. Field capacity improved by 78% from early to late succession, while wilting point increased by 45%, resulting in a 156% increase in plant-available water capacity. Temporal analysis revealed that SOC-moisture coupling strengthens progressively during succession, with correlation coefficients increasing from r = 0.42 in early stages to r = 0.91 in old-growth forests. Microbial biomass carbon exhibited strong relationships with both SOC (r = 0.89) and soil moisture (r = 0.77), indicating coupled biogeochemical-hydrological controls on ecosystem functioning. Structural equation modeling identified SOC as the primary driver of moisture retention, while soil moisture reciprocally influenced SOC accumulation through effects on decomposition rates and plant productivity. Economic valuation of these coupled ecosystem services revealed benefits of $340-890 ha⁻¹ year⁻¹ for carbon sequestration and $180-450 ha⁻¹ year⁻¹ for hydrological regulation in mature forest stands. These findings demonstrate that SOC and soil moisture dynamics are intimately coupled during forest succession, with important implications for ecosystem resilience, climate change adaptation, and forest management strategies.