Diethanolamine and maleic anhydride were used as the starting materials to to synthesize hyperbranched unsaturated poly (amide-ester) HP. The anionic-nonionic hyperbranched surfactant HPSA-4 was synthesized by the esterification of succinic acid monolauramide sulfonic acid and HP. The HPSA-4 and characterized by Fourier transform infrared (FTIR), 1HNMR and GPC。The CMC, SFT, IFT, wetting properties, anti-aging properties under high temperature and high salt, emulsifying properties and oil displacement of HPSA-4 were tested. The results showed that the cmc of HPSA-4 was 0.162 g•L-1, γcmc=23.4mN/m, δcmc=0.07mN/m. Under high temperature(150℃) and high salt(ωNaCl=2*105mg/L), the surface tension is about 25mN/m after aging 15 days. Besides, HPSA-4 has good wetting properties and wetting reversal properties. Moreover, the emulsification performance of HPSA-4 is comparable to that of sodium dodecyl sulfonate, but its emulsification performance under high salt(ωNaCl=8*104mg/L，ωCaCl2 =104mg/L) is superior to that of sodium dodecyl sulfonate. The core flow test indicate that 0.3g/L HPSA-4 can improve EOR about 5.3% on the basis of water flooding when the injection volume is 0.5 PV. All the above studies indicate that HPSA-4 can be used as an oil displacement agent in high temperature and high salinity oilfield.