AM/AMPS copolymer was synthesized in aqueous solution using adiabatic reaction. The polymerization was initiated by (NH4)2S2O8-NaHSO3 as the redox initiation system, and TMEDA, urea and EDTA-2Na were added at the same time. The exothermic process of adiabatic polymerization, the structure and the properties of copolymer were investigated. The results showed that the molecular weight of copolymer could reach 2.5×107 by falling initiation temperature and reducing initiator concentration, and the solubility of copolymer was perfect. In addition, the copolymer solution had significant capacities of increasing viscosity, excellent heat resistance and salt tolerance, and strong viscoelasticity at high temperature. The viscosity retention rate of copolymer solution was as higher as 84.2%, under the condition of fresh brine, 95℃ and a 60-day aging test. The polymer flooding could enhance oil recovery by 17.38% according to simulation displacement evaluation.