Abstract: Fractured reservoirs in the eastern South China Sea contain numerous complex fractures and cavities. Supersaturated packing is an effective method to control bottom water breakthrough. To better enhance the effectiveness of supersaturated packing technology and improve overall water control and oil production in field development, this study takes a horizontal well as an example. Based on the particle packing mechanism of fractured reservoirs and combined with laboratory packing experiments and numerical simulation analysis, a method for determining fracture opening pressure was established, and a predictive method for the fracture packing pressure threshold was derived. After implementation on the field site, the particle packing rate reached approximately 245%, with a maximum packing pressure of 9.2 MPa. The initial oil production exceeded the allocated production by over 40%, and the water cut decreased by more than 45%, demonstrating significant results. The optimization of the supersaturated packing process provides a clear idea for the efficient development of this type of reservoirs and holds substantial reference value.