In order to improve the oil displacement efficiency of offshore oilfields and meet the operational requirements of offshore platforms，an emulsion polymer gel system suitable for deep flooding of offshore oilfields was obtained by measuring the viscosity of emulsion polymer solution and gel system with time. The sealing performance and oil displacement effect of the emulsion polymer gel were studied by a sand-filling model plugging experiment with a length of 1 m and a homogeneous core flooding experiment. The results showed that the stability of the emulsion polymer was good，and the viscosity retention was 71.15% after the solution was placed for 31 days. The polymer gel consisting of two phenolic cross-linking agents and an emulsion polymer had a gelation time of 8 days and a gelling viscosity of 911 mPa·s indicating good stability. When the injection rate of water flooding and polymer flooding was 5 m/d，the plugging effect of the sand filling model was relatively good，and the plugging rate along the sandpack was more than 90%. In the core flooding experiment，the recovery degree increment of the core with a permeability of 5000×10^-3μm² was 12.46% and 3.83% higher than that of 1000×10^-3μm²and 3000×10^-3μm². Therefore，the polymer gel system couldenter the deep part of the reservoir to achieve deep adjustment and drive under high permeability conditions，and improve the effectof water flooding.