Aiming at the problem that heavy oil have high viscosity，while the pure polymer flooding has poor affinity with crude oil and the displacing efficiency and enhancement of oil recovery is low，the viscosity reduction experiments of the heavy oil in offshore S using a polymer emulsifier RH327 was carried out，and the emulsion type，the emulsion concentration，the aggregation morphology，the wetting ability，the stability and the static/dynamic adsorption capacity were evaluated under reservoir conditions. On the basis，the flooding performance of RH327 were evaluated through physical simulation，and novel polymeric emulsifier system that could enhance oil recovery substantially was established. The results showed that，at lower concentrations（1.2 g/L），the viscosity reducer RH327 had strong emulsifying activity under the reservoir environmental conditions，the viscosity of crude oil could reduced by 94.7% at oil-water ratio of 50∶50；at the same time，RH327 also had fast emulsification speed and strong emulsification stability，the emulsification rate being of 0.17 mL/min. The static adsorption of RH327 at higher concentrations of 2g/L in the oil sands was only 3.4 mg/g，the saturated adsorption of the artificial core with the permeability of 2756.15×10^-3 μm² could be attained after injecting 2.5 PV RH327 solution with the concentration of 1.6 g/L，the saturated adsorption capacity being of 160 ug/g. Physical simulation results showed that when main viscosity reducing agent slug was 0.3 PV and polymer protective slug（amphiphilic acrylamide polymer ICGN）with concentration of 1750 mg/L and slug size of 0.06 PV was conducted，the RH327 solution could enhance the oil recovery by 17.3% based on the water flooding（35.72%）