During the seepage of ternary compound system in reservoir，displacing capacity of the system dynamically changed due to the shear degradation of polymer and the adsorption and retention of surfactant，which affected the actual displacing ability of compound system as it reached deep reservoir. In order to determine the property variations of compound system and its effect on oilrecovery during flooding process，the effect of seepage velocity and migration distance on the viscosity of compound system and the dynamic distribution characteristic of oil/water interfacial tension along the flow direction were investigated. The influence of property variation of compound system on oil recovery was also studied. The results showed that seepage velocity and migration distance had great effect on viscosity and oil/water interfacial tension of compound system. The viscosity decreased obviously with increasing seepage velocity. When the seepage velocity was greater than 10 m/d，the viscosity decrease became inconspicuous. The shear degradation of compound system mainly occurred in inlet or near wellbore，and the increased migration distance did not cause a significant viscosity decrease after entering deep model or reservoir. The interfacial tension of compound system increased significantly with increasing migration distance. The compound system could only form ultra-low interfacial tension on the injection end or near wellbore when the injection volume was small，while it could reach ultra-low interfacial tension on deep model when 3.0 PV compound system was injected. The influence of interfacial tension variation of compound system on oil recovery was more significant than that of viscosity. And it was the key of chemical combination flooding to keep ultra-low interfacial tension as the system reached deep reservoir.