Fatty alcohol polyether sulfate anionic-non-ionic surfactant (PES) was synthesized using aliphatic alcohol block polyether, a kind of polyoxypropylene polyoxyethylene ether (PEOH), and chlorosulfonic acid as raw materials. The structure was characterized by FTIR, 1H NMR, MS, and a laser particle size analyzer, and mixed with heavy alkylbenzene sulfonate (HABS) to build a PES/HABS system. The interfacial tension, foam properties, emulsification ability, emulsion type, and stability were determined. At the same time, the deoiling effect of the optimized PES/HABS and polymer composite alkali-free flooding system was tested. The results showed that when PES concentration was 0.3% and NaCl content was 1.6%, the oil-water interfacial tension could be reduced to 8.27 × 10-3 mN/m.The optimal composite system was achieved at a PES-to-HABS mass ratio of 4:6. The interfacial tension between oil and water is maintained to 10-3 mN/m within 0.4-1.6. With the increase of salinity, the emulsion undergoes a phase transition process from Winsor I to Winsor III and then to Winsor II. Winsor III emulsion can be stably formed within the range of NaCl mass concentration of 0.6%-1.9%, with an average particle size of 13.3 μm and a TSI of 5.43, showing good salt resistance and emulsion stability. In addition, the oil solubilization amount is as high as 70 mL/g, which has a good solubilization effect. Compared with water flooding, the oil recovery factor increased by 32.6 percentage points.