The heterogeneity of complex fault block reservoir is strong, preferential seepage channels are formed between injection and production wells after long time development by water flooding, resulting in ineffective circulation of injected water and poor water flooding development effect. The application of ‘combination of two and three’ enhanced oil recovery technology can effectively improve the poor adjustment effect of water flooding, and the construction of reasonable well pattern is the key to the success of ‘combination of two and three’ in water flooding reservoirs. In view of the characteristics of small oil-bearing area, development of preferential seepage channels after water flooding and complex distribution of remaining oil in complex fault block reservoirs, the methods of physical simulation, numerical simulation and field statistics are used to focus on the well pattern reconstruction form of realizing the orderly connection between ‘secondary adjustment well pattern’ and ‘tertiary oil recovery well pattern’ and maximizing benefits, so as to meet the needs of efficient development of complex fault block reservoirs in the total life cycle.