Abstract: Rock microscopic pore throat is an important factor to characterize the physical properties of the reservoir. At present, the core physical property analysis data available under the condition of few wells at sea are limited. In order to quantitatively describe the microscopic pore throat characteristics and physical properties of the Pinghu Formation reservoir rocks in X oilfield of Xihu Sag, the capillary pressure curve method and CT scanning digital core technique were used to characterize the microscopic pore throat of the oilfield, and the comparative analysis was carried out. The capillary pressure curve method uses the mercury injection experiment to measure the core rock sample data, and obtains the displacement pressure and pore characteristic parameters through the capillary pressure curve plate. CT scanning digital core technique is used for 3D digital core reconstruction of rock samples. The constructed 3D digital core has high similarity with the real core. Combined with the maximum ball method and image processing methods, the quantitative and visual characterization of rock microscopic pore throat is achieved. The shape trend of pore distribution curve obtained by the capillary pressure curve method and CT scanning digital core technique is consistent, but there are differences. This paper intends to compare and analyze the application of capillary pressure curve method and CT scanning digital core technology in microscopic pore throat characterization, aiming to provide more accurate and comprehensive reservoir characterization information for researchers and provide theoretical guidance for oil and gas exploration and development.