In order to solve the problems of degradation, failure, salt crystallization and salt deposition of traditional fracturing fluid in high temperature and high salinity environment, which lead to the decrease of fracturing fluid performance, an associative viscoelastic polymer P(AM/AA/AMPS/APEG) was prepared by inverse emulsion polymerization using acrylamide (AM), acrylic acid (AA), 2-acrylamido-2-methylpropanesulfonic acid (AMPS) and hydrophobic monomer allyl polyethylene glycol (APEG) as molecular skeletons. The structure and morphology of the polymer were characterized by FT-IR, 1H-NMR, SEM and laser particle size analyzer, and its rheological properties, thixotropy and viscoelasticity were evaluated. The results show that the polymer solution is viscoelastic fluid, and the polymer P(AM/AA/AMPS/APEG) solution with a 0.8% concentration shows good temperature resistance at 160 ℃. The viscosity of polymer P(AM/AA/AMPS/APEG) is 64.88 mPa·s and 64.88 mPa·s after shearing in a 20 g/L NaCl solution and CaCl2 solution at 140 ℃ and 170 s-1 for 1 h, respectively.