A zwitterionic copolymer (ANND) containing twin-tail structure was synthesized using acrylamide (AM), acrylic acid (AA), N,N-dioctylmethacrylamide (DLMB) and 3-(2-methacrylamidopropyldimethylamino)propane sulfonate (MDPS) via free-radical copolymerization. The copolymer was characterized by FT-IR, 1H NMR and TG-DTG to confirm that it was prepared successfully and had favorable thermal stability. And compared with partially hydrolyzed polyacrylamide (HPAM), the thickening property, water solubility, aging resistance, shear thinning, temperature tolerance and salt resistance of the copolymer were investigated. The results showed that the copolymer had excellent water solubility and thickening property, and its apparent viscosity could reach 466.5 mPa·s at 2000 mg/L. The apparent viscosity of the copolymer could remain 60.4 mPa·s under 510 s-1 and 182.6 mPa·s at 120 oC. And the viscosity retention value of AADM could remain 94.6 mPa·s after 30 days of aging. When the copolymer was dissolved in 15000 mg/L NaCl, 2000 mg/L MgCl2 and 2000 mg/L CaCl2 solutions, the apparent viscosity of these copolymer solutions were 77.8, 72.4 and 68.6 mPa·s, respectively. Core flooding experiment further indicated that the copolymer solution could enhance oil recovery by 7.72%. The above experimental results are superior to those of HPAM under the same conditions, because the introduction of the twin-tail structure effectively enhances the hydrophobic association ability of the copolymer, and the introduction of the zwitterionic monomer weakens the sensitivity of the molecular chain to the salt.