In view of the practical problems of existing commercial foams in high temprature，high salinity and low permeability reservoirs，such as low foaming volume，poor foam stability in porous media and low oil displacement efficiency，two kinds of asymmetric amphoteric gemini surfactants PAHC and PAOC were synthesized by etherification，quaternization，and substitution reactions as foaming agents for CO₂ foam flooding. The synthesized PAHC and PAOC was used as the main foaming agent to prepare a CO₂ foaming system. The interfacial activity，temperature and shear resistance，viscoelasticity and foam properties of the foaming system were evaluated，and the displacement experiment was carried out. The critical micelle concentration c_cmc of PAHC and PAOC were 6.76×10^-5 mol/L and 5.25×10^-5 mol/L，respectively，and the corresponding surface tension γ_cmc were 31.56 mN/m and 30.71 mN/m，respectively，and the Krafft points of PAHC and PAOC were lower than 0 ℃ and 1 ℃，respectively，which indicated that the two surfactants had good surface properties. Under the conditions of Gao 21-3 well in the second oil production plant of Jiangsu oilfield，the reservoir temperature being of 80 ℃ and the salinity being of 7704 mg/L，at a constant shear rate of 170 s^-1，the temperature resistance of PAHC-C₁₆S and PAOC -C₁₈S foaming systems were 81 ℃ and 88 ℃，respectively，and the viscosity of the two systems could be maintained at 6.2 mPa s and 6.4 mPa s，respectively，which exhibited that the injection and the viscoelastic properties of the two foaming systems were good. The PAHC-C₁₆S and PAOC -C₁₈S foaming systems could reduce the oil-water interfacial tension to 2.37×10^-2 mN/m and 1.81×10^-2 mN/m，respectively. The PAHC-C₁₆S and PAOC -C₁₈S foaming system had good temperature and salt resistance，and the temperature and salt resistance of PAOC -C₁₈S foaming sysmtem was slightly better than that of PAHC-C₁₆S foaming foam，which could be used in CO₂ foam flooding in high temperature and high salinity reservoirs such as Gao 21-3 well in the second oil production plant of Jiangsu oilfield. The core oil displacement experiment results showed that the average EOR of PAHC-C₁₆S and PAOC -C₁₈S foam systems on the basis of CO₂ flooding were 20.12 percentage point and 21.91 percentage point，respectively，which showed that the foaming system had good recovery effect.