In response to the problems of low oil recovery rate and high adjustment limit in complex faultblock oil reservoirs, the new development concept of ‘secondary-tertiary combination’ is applied, and the T25 block is taken as an example to explore the collaborative acceleration technology of water flooding and polymer flooding in foreign dividing developed oilfields. On the basis of detailed geological research, taking into account the distribution characteristics of remaining oil in the block and economic benefits, the high structural areas are selected to form a five point polymer flooding well network for well network reconstruction. 22 development wells are deployed to reduce the well spacing from 250 to 177 m, in order to meet the needs of water flooding and polymer flooding collaborative development. After drilling the development wells, measures such as early conversion of polymer injection wells and subdivision of water injection are taken to form a three-dimensional potential tapping mode with weak points and strong surfaces on the plane, and strong suppression and weak enhancement on the vertical direction. The oil recovery rate is increased by 0.33% and maintained at 1.25% for more than two years, achieving good water flooding potential tapping effect. Research has shown that the application of the ‘secondary-tertiary combination’ water flooding and polymer flooding collaborative development technology can improve oil recovery rate, achieve the goals of early oil extraction, fast oil extraction, multiple oil extraction, and early cost recovery, providing reference for the development of similar oil fields.