The undisturbed soil samples from the profiles of different reclamation areas in Rudong County, Dongtai City and Binhai County of Jiangsu Province were taken as the research objects. Based on CT scanning technology, through the construction of pore network model, the soil pore distribution and its topological relationship were quantitatively characterized, and the soil pore throat parameters, including pore size distribution, coordination number, throat radius and throat length, were statistically analyzed. Using the extracted pore network, the seepage simulation of single-phase water in soil was realized, the absolute permeability coefficient (saturated hydraulic conductivity) of soil and its main influencing factors were analyzed. The results showed that the reclamation activities played a positive role in improving soil pore activities. The specific performance was that with the increase of reclamation years, the radius range, average coordination number and throat radius of connected pores tended to increase, while the throat length tended to decrease. The pore structure of shallow soil layer was better. In single-phase water simulation, the simulated permeability coefficient was in good agreement with the measured saturated hydraulic conductivity, showing a consistent change trend. The grey correlation degree showed that the throat radius had the greatest influence on soil permeability.