Abstract: After 13 years' development, degree of oil recovery of Pinghu Oilfield has reached 41% and water cut is 96%. In view of complicated distribution of residual oil and no candidate reservoirs, some methods to improve oil recovery ratio was proposed in this pa-per including fine interbed analysis, geo-modelling, simulation, layer recombination, water shutoff, log re-interpretation for old well, well shut-in for deconing, etc. After using these methods on different oil wells, oil production rate increases in a period of time and production decline was slow down, and these methods can be used as reference for similar oil fields at extra high water cut period.