The oscillating water column buoy utilizes wave energy by channelling waves into an air chamber, inducing oscillations within the water column. However, wave impact also causes buoy oscillation and rocking, which reduces the relative water column displacement. To address this, a double-layer concave damping plate with a weight-enhancing ring was implemented to stabilize buoy movement. A double-concave damping plate with a weight-enhancing ring was used to inhibit the movement of the floating buoy and increase the pressure of the air chamber. Based on the small amplitude wave theory and Newton's second law, a theoretical model was developed to analyze wave energy capture by the damping plate-enhanced oscillating water column buoy, calculating buoy oscillations and air chamber pressure characteristics. The finite element simulations, conducted using AQWA software, replicated the wave-induced hydrodynamic effects on the buoy. Air chamber pressure was simulated via Fluent software's fluid volume method and open channel wave-making method, and the model's accuracy was validated against theoretical calculations. The simulation results show how effective the damping plate is in limiting buoy motion, raising mass and buoy inertia, and improving water column stability in the air chamber. The theoretical calculation of the air chamber air pressure parameters provides a basis for the design of the damping plate oscillating water column buoy wave energy harvesting system and the green low-carbon energy conversion structure.