Aimed at the 80℃ high temperature reservoir after polymer flooding, Petroleum sulfonate 1# was chosen and used for the surfactant/polymer (SP) system. The effects of surfactant concentration, polymer concentration, salinity and fresh water on interfacial tension were studied, and then the long period heat resistance of the SP system, adsorption of surfactant on the Shuanghe oil sand, injectivity was studied and oil displacement experiments were carried out. The results showed that the surfactant 1# had a very good interfacial activity. The interfacial tension between the SP system and the crude oil could be reduced to ultra-low (10-3mN/m) when the concentrations was of 0.1%—0.5%. The polymer had little effect on it. The SP system had good salt tolerance and thermal stability, the interfacial tension could keep 10-2 mN/m after kept in 80℃ drying oven for 90 days. The surfactant adsorption of the SP system was lower than that of single surfactant on Shuanghe oil sand. The SP system had a good injectivity. The core flooding test showed that low interfacial tension system could enhance the higher oil recovery efficiency. The system composed of polymer concentration 1800 mg/L and surfactant concentration 3000mg/L could enhance the oil recovery of 10.26% after polymer flooding.