A series of branched polymer surfactant (PSA) was prepared by using hydrogen silicone oil (PHMS), allyl polyether(FB1000) and different content of eighteen acrylic ester(SA) as raw materials. The structure and the solution property of polymer was characterized and investigated by infrared spectroscopy (FT-IR), nuclear magnetic resonance(NMR), gel permeation chromatography(GPC), surface tension, dynamic light scattering (DLS) and fluorescence spectroscopy (FLD). With the increase of SA content, it is easier for polymer to associate and aggregate together to form micelles, the particle size increased from 71.40nm to 141.07nm and the dispersion coefficient increased to 0.396. Moreover, the surface tension of polymer solution reduced to 24.20mN/m, and critical micelle concentration (cmc) decreased to 0.49g/L as increasing the content of hydrophobic groups. The fluorescence spectra showed that hydrophobic microdomain was formed with an increase in the PSA concentration, and the first and third emission peak ratio gradually decreased. Pyrene molecules dissolved into the micelles and I1/I3 value kept almost invariable when the PSA concentration was greater than the critical aggregation concentration (cac). The demulsification experiments demonstrated that the dewatering ratio of PSA demulsifier is up to 93%.