Abstract: The turnover and stabilization of soil organic carbon is the core element of carbon sequestration mechanisms. The addition of biochar could alter the soil environment, thereby manipulating the structure and function of soil microbial communities, and exerting a profound influence on soil carbon sequestration functions and carbon pool dynamics. In this study, the effects of biochar addition on carbon components, carbon pool management index, and carbon cycling functional genes of reclaimed soil from coal mining subsidence areas, were explored through employing pot simulation experiments, high-throughput sequencing, and structural equation modeling techniques. The research target was to identify feasible pathways for carbon sequestration and sink enhancement in reclaimed soil. The results showed that: ① Biochar addition significantly increased the soil total organic carbon (TOC) and particulate organic carbon (POC) contents, while these augments were proportional to the amount of biochar added. The soil TOC content in the 5.0% corn straw biochar (CB) treatment group increased by approximately 139.4%, whereas the increasing proportion of POC content was particularly significant, reaching as high as 259.2%. Different proportions of biochar addition performed varying effects on soil microbial biomass carbon (MBC), with low proportions presenting a promoting effect and high proportions showing significant differentiation. Among them, the CB treatment group had a significant impact on MBC, with the largest increase at a 1.0% addition amount, reaching up to 274.15 mg·kg⁻¹. However, there was a consistent significant difference in the impact on dissolved organic carbon (DOC). ② The carbon pool management index of reclaimed soil increased by 4.7%, 4.8%, and 24.0% with the addition of rice straw biochar (RB), wheat straw biochar (WB), and corn straw biochar (CB), respectively. Compared with the control treatment group, the absolute abundance of CBBL (Ribulose bisphosphate carboxylase large subunit gene) in the RB, WB and CB treatment groups was significantly increased (p<0.05). There were significant differences in the absolute abundance of PMOA (Particulate methane monooxygenase gene) among different biochar additions (p<0.05). ③ Spearman correlation analysis indicated that microbial biomass carbon was an important factor in characterizing soil carbon pool dynamics. The addition of biochar significantly altered the relationships between soil carbon components and carbon sequestration functional genes and the carbon pool management index, enhancing the correlation and closeness between soil microbial communities and carbon sequestration functional genes and the carbon pool management index, with the CB treatment being the most significant. ④ Biochar addition changed the physicochemical properties of reclaimed soil, thereby affecting soil carbon components and soil enzyme activities, and ultimately influencing soil carbon pool dynamics. At the same time, it might affect the structure and function of microbial communities, thereby altering the abundance of carbon sequestration functional genes and regulating soil carbon pool dynamics. This research indicates the adaptation and mechanism of biochar addition on carbon components, microbial community functions, and carbon pool dynamics of reclaimed soil, providing theoretical support for carbon sequestration and sink enhancement in coal mining subsidence reclaimed soil.