In order to deeply understand the influence law of emulsifying ability and interfacial tension on oil displacement effect of binary oil displacement system，seven systems，including 0.3% KPS + 0.1% HPAM（a）0.5%Span/0.5%Twain+0.1% HPAM（b），0.3% ZS + 0.1% HPAM（c），0.3%YC（d），0.3% HPS + 0.1% HPAM（e），0.3% SP + 0.1% HPAM（f），0.3%ZS + 0.1%HPAM +0.4%Na2CO3（g），were selected for researching on the internal correlation between dynamic emulsification characteristics，dynamicinterfacial tension and oil displacement effect. Water-separating test and interfacial tension measurement showed that emulsification index was in range of 0 to 0.38，the interfacial tension was in range of 10-3—10 mN/m. The emulsification characteristics of thesesystem could be divided into five types：“non-emulsification”（system f），“emulsification reversal”（system e），“former-process emulsification”（system a），“rear-process emulsification”（system d）and“whole-process emulsification”（system b，c and g），interfacial tension peculiarity was divided into 7 types：“L”type（system a），“—”type（system b），“shallow dish”type（system c），“G”type（system d），“V”type（system e），“\”type（system f），“deep bowl”type（system g）. Core displacement test revealed that the stronger of emulsifying ability was，the higher recovery efficiency of the secondary water flooding had. For“\”system f with“non-emulsification”，“shallow dish”system c with“whole-process emulsion”and“G”system d with“rear-process emulsion”，the secondary water flooding recovery was 0.36%，4.25%，0%，respectively，that due to the interlaced action of the emulsify on mobility control and interfacial tension on capillary number effect. In addition，by compared the residual oil distribution after polymer and the binary compound flooding，uneven distribution of residual oil after binary flooding was found and "white spot" was prone to form because of unreasonable slug collocated，so the interfacial tension and the emulsification was not enough to offset the out of control mobility. Therefore，the displacement system with ultra-low interfacial tension and whole-process emulsion capacity should be preferred to and the fluidity control should be intensified in binary compound flooding technology