The secondary development of mature oilfields with high water cut is a revolution in the history of oilfield development and also a strategic systematic project. It plays an irreplaceable role in maintaining long-term stable oil production. From the aspects of intelligent decision-making, intelligent planning, intelligent operation, intelligent monitoring, and intelligent evaluation, and within the framework of the policies for carbon peaking and carbon neutrality, the prospects for the secondary development of mature oilfields in China were discussed. It is indicated that the secondary development of mature fields should be implemented by reconstructing underground understanding system, well pattern, and surface process, and technically by way of overall control, stratigraphic subdivision, plane reorganization, three-dimensional optimization, and deep profile control, ensuring the smooth integration of secondary development and tertiary development.