The edge well group of Bohai B oilfield has the characteristics of low reservoir permeability and high water injection pressure，and the water flooding development effect is poor. In order to enhance oil recovery，the research on reducing oil-water interfacial tension and improving rock wettability by pressure flooding agent was carried out. On this basis，the physical simulation of synergistic pressure flooding and the optimization of process parameters of target wells were carried out. The results showed that the interfacial tension between TYT303，UST and GWQY fluid and the crude oil of the target reservoir was low，and ZF-6，SXJ-1 and SXJ-2 had strong ability to change the wettability of the core，ZF-6，SXJ-1 and SXJ-2 could reduce the contact angle by more than 60°. Through physical simulation experiments，the optimized synergistic pressure flooding process conditions were obtained as follows，the pressure flooding working fluid was 0.3% ZF-6，the reasonable slug size was 0. 3 PV，the shut-in time was 48 h，the injection round was about 3 times，and the appropriate increase of fracture length and injection rate was beneficial to enhance oil recovery. It was recommended that the target well group should adopt the stimulation measure of“fracturing-imbibition-oil displacement”. The key process parameters were injection displacement of 5 m³/min，liquid injection volume of 18000 m³ and shut-in time of 15 days.