Carbon storage of wetland ecosystem plays an important role in the terrestrial ecosystem carbon cycle and holds important ecosystem service functions. Baiyangdian Wetland is a national key ecological wetland and the largest freshwater wetland in the North China Plain. As the core water system in the Xiong'an New Area, it is critical to estimate the soil carbon storage in Baiyangdian Wetland, which will provide data support for ecosystem service evaluation and wetland ecosystem restoration. In this study, 105 soil profiles in seven different vegetation types in Baiyangdian wetland region were layered and sampled. The spatial distribution of soil organic carbon density and storage were clarified based on physical and chemical analysis in laboratory and statistical analysis. The results showed that: (1) the average Soil Organic Carbon (SOC) content in the surface soil (0-20 cm) in Baiyangdian wetland is 8.53-17.70 g/kg, which is relatively lower than those of the other wetlands. The SOC content varied among different vegetation types and the organic carbon content in reed marsh is about three times than that of the other land use types. (2) In terms of the vertical distribution characteristics, the SOC in Baiyangdian wetland decreased as the increase of the soil depth, and it is highest in the surface layer (0-20 cm), which account for about 30% of the total amount of the soil. (3) The dynamics of density and content of SOC is consistent and it varied according to the vegetation tapes. It showed that the garden plot < dry land < evergreen coniferous forest < deciduous broad-leaved forest < paddy field < ota reed < flooded reed. The organic carbon density of flooded reed (24.36 kg/m²) is significantly higher than that of the other vegetation types. (4) The total amount of SOC storage in this region is 5816.77×10³ Mg. With the environmental improvement in the Xiong'an New Area, Baiyangdian Wetland will continue to increase its ecosystem carbon sequestration. It is of great significance for regional ecological benefits to combine with ecological restoration and land layout optimization, and minimize the carbon emissions due to land transfer in the construction of the Xiongan New Area.