Fatty alcohol polyoxyethylene ether (AEO) and acrylic acid (AA) as raw materials were synthesized by esterification reaction, and then a negative non-ionic polymer surfactant (P-AASL) was prepared by free radical polymerization with sodium styrene sulfonate (SSS) and dodecyl acrylate (LA). The structure and molecular weight distribution of P-AASL were characterized by FTIR, 1H NMR and GPC. The aggregation structure of P-AASL in solution was characterized by DLS and TEM. The surface interfacial tension, wettability, salt resistance and thermal stability of P-AASL were tested by DSC, contact Angle tester and surface and interfacial tension tester. The effects of different m(P-AASL):m(sodium petroleum sulfonate) (1:9~5:5) on the surface boundary activity and oil washing efficiency of the composite surfactant system were investigated. The results show that P-AASL belongs to the macromolecular surfactant, its number average molecular weight (Mn) is 12121, weight average molecular weight (Mw) is 14027, and polydispersion index is 1.157. P-AASL is a spheroidal micelle with an average particle size of 141.7 nm and a polydispersion index of 0.136. The critical micelle mass concentration of P-AASL solution is 0.62 g/L, and the lowest surface tension is 33.4 mN/m. P-AASL solution with 0.3% mass fraction can reduce the oil-water interfacial tension to 1×10-1 mN/m, and reduce the water-contact Angle of oil-wet natural core to less than 40°. P-AASL thermal decomposition occurs at 300 ℃ or above. The tolerance of P-AASL to NaCl and CaCl2 in aqueous solution was 140 g/L and 8 g/L, respectively. The interfacial tension between crude oil and water can be reduced to 1×10-3 mN/m when the mixture ratio is 8:2, the emulsification water separation time of crude oil is more than 50 min when the mixture ratio is 5:5, and the oil washing efficiency is about 77% when the mixture ratio is more than 3:7.