The invention discloses a hydrophobically associated polymer-composite surfactant binary combination flooding system and method. The hydrophobically associated polymer-composite surfactant binary combination flooding system mainly comprises the following components in percentage by weight: 0.08-0.3 wt% of hydrophobically associated polymer, 0.05-0.5 wt% of composite surfactant and 99.2-99.87 wt% of water. The composite surfactant is composed of the following components in percentage by weight: 50-70 wt% of fatty acid diester disulfonate and 30-50 wt% of oleic acid diglycollic amide. The hydrophobically associated polymer-composite surfactant binary combination flooding system has favorable tackifying property, and enables the oil-water interfacial tension to reach 10<-3>nM/m under low surfactant concentration (0.05%), thereby enhancing the displacement efficiency; and the hydrophobically associated polymer-composite surfactant binary combination flooding system can enhance the recovery rate by more than 30% on the basis of water flooding, lowers the polymer consumption by more than 50% as compared with the 250-million ultrahigh-molecular-weight polyacrylamide binary combination flooding system with close properties, and enhances the recovery rate by 6%, thereby greatly lowering the oil displacement cost on the premise of increasing the yield.