Conventional polymer is easy to degrade and difficult to inject in extra-high temperature（95-120 ℃）and midlow permeability（50-100 mD）reservoirs. Evaluation method of emulsifying property and thickening property of the emulsion-surfactant was established for enhancing oil recovery of the extra-high and mid-low permeability reservoirs. Structure-activity relationship of the emulsion-surfactant was researched. The emulsion-surfactant flooding system was developed. The viscosifying emulsion was formed at 110 ℃ with more than 90% of solubilizing water ratio and more than 100% of viscosity increase rate by emulsification. The physical simulation results showed that the oil recovery was improved by 17.7%-22.1% when emulsion-surfactant flooding system（emulsified-viscosifying emulsion surfactant and low IFT surfactant）was injected into the system alternately for several times. The pilot test of emulsion-surfactant flooding was carried out in Chun17-1 unit of Chunhua Oilfield. Three cycles were injected alternately in February 2017，and the obvious oil increasing effect has been observed in the oil wells. Emulsion-surfactant flooding technology has created a new type of development method，which provides technical support for enhancing oil recovery in the extra-high temperature and mid-low permeability reservoirs.