As a new energy source with abundant resources, clean combustion, and high calorific value, gas hydrates have received much attention in recent years. However, the sampling cost is relatively high because the gas hydrates exist in deep seas and frozen soils. Digital core technology can reconstruct hydrate cores without destroying rock samples. In this paper, the advanced image processing technology is used to process the gas hydrate computed tomography (CT) scan image, and a three-dimensional hydrate digital core model is constructed, which can depict the sample's pore structure features. avizo software is used for filtering and image segmentation; the porosity is calculated as 35.90%, the hydrate saturation is 36.92%, and the pore network model is established. The pore radius is mostly distributed in 0–1 × 102 µm, and the average pore radius is 168.131 µm; the throat radius is mostly distributed in 0.5–1×102 µm. The seepage simulation on the pore scale is carried out, and the absolute permeability is calculated to be 76.8 µm2. Compared with conventional physical experiments, the digital core technology can obtain the true distribution of the pores inside the hydrate core, which is very helpful for analyzing the physical parameters of the hydrate core. The digital core technology is of great significance in the study of hydrate reservoirs.