Soil C pools recover very slowly following severe wildfire disturbance. It remains unclear whether forest management could enhance C accumulation in post-fire degraded soils. This study investigated changes in soil C mineralisation in Betula platyphylla forests (formed through secondary succession on intensely burned sites) following thinning operations. To compare the effects of thinning, B. platyphylla forests at 2 years (2a), 14 years (14a), and 17 years (17a) post-thinning were compared with unthinned control (CK) plots. The results indicate that thinning significantly influenced C mineralisation in post-fire degraded soils at the 0-10 cm depth, while no significant differences in the 10-20 cm depth were observed. Compared to the CK, the greatest increase in cumulative soil carbon mineralisation occurred at the 0-5 cm depth, with 14a and 17a at + 20.35 % and + 19.31 % respectively. A non-linear equation was used to fit the kinetic equation for C mineralisation. Both 14a and 17a exhibited higher potential mineralisable C than CK at the 0-10 cm depth, yet lower mineralisation rates (K). Conversely, 2a demonstrated significantly higher K values than CK at this depth. This suggests that while the long-term effects of thinning may enhance soil carbon accumulation by reducing mineralisation rates, while the short-term effects exert a stimulating effect on soil C mineralisation. RDA and VPA analyses revealed that individual site-specific environmental factors explained over 79 % of carbon mineralisation variation, with primary influences being soil C fractions, C/N, Understorey Vegetation Biomass (UVB), and soil physicochemical properties. However, when analysing different post-thinning time points collectively, environmental factors explained 81.10 % (0-10 cm) and 66.20 % (10-20 cm) of soil C mineralisation variation in the heavily burned plot. Among these, UVB (shrubs and herbaceous plants) was the key regulator of soil C mineralisation at the 0-10 cm depth, explaining 41.50 % of variance. POC & EOC exhibited similar explanatory power across the 0-20 cm profile, accounting for 23.60 % (0-10 cm) and 28.90 % (10-20 cm), respectively. Pathway analysis further revealed that UVB radiation directly positively regulates C0. It also indirectly influences carbon mineralisation processes by promoting the formation of active organic carbon fractions. Furthermore, dissolved organic carbon directly contributes positively to carbon mineralisation rates, whilst soil bulk density consistently exhibits a negative regulatory effect. This study further indicates that understorey vegetation may represent a significant regulatory pathway in soil recovery processes involving forest management interventions.