Soil organic carbon (SOC) constitutes a vital component of the soil carbon pool. This study uses the DeNitrification-DeComposition (DNDC) model to simulate soil organic carbon under traditional tillage systems in Huainan City, validates it with Soil Basic Nutrient Dataset for Soil Testing and Formula Fertilization (2005-2014) and field sampling data, and performs combination simulations of different tillage methods, types of fertilizers, and straw return amounts to select the optimal combination. Analysis shows that the DNDC model fits the organic carbon in the farmland soil of Huainan City well. The DNDC model combined with the response surface model indicates that the best carbon sequestration effect is achieved with no-till + chemical fertilizer combined with organic fertilizer + full straw return, with a carbon sequestration rate (124%) significantly higher than that of traditional tillage systems (29%). Furthermore, SOC simulations under conventional climate, RCP2.6, and RCP6.0 conditions indicate that the rate of increase in soil organic carbon decreases with rising CO2 concentrations and temperatures. Therefore, promoting appropriate no-tillage + chemical and organic fertilizers + full straw return in Huainan's farmlands could enhance soil organic carbon and carbon sequestration capacity, while advancing emission reduction technologies to mitigate the impact of climate change on soil organic carbon.