Based on free radical polymerization, a series of temperature and salt resistance amphiphilic polymers viscosity reducer were synthesized by using haloalkanes, polyethyleneimine(PEI), acrylamide(AM), 2-acrylanmido-2-methylpropanesulfonic acid(AMPS). By infrared spectrum(IR), microscope, Rotary interface tensioner, haake rheometer and sand pack experiment, the viscosity reduce property and flooding performance of polymers on Chunfeng heavy oil were studied. Experimental results showed that when the polymer mass fraction is 1.00% and the oil-water mass ratio is 7:3, the heavy oil with viscosity of 4753 mPa?s in Chunfeng oilfield can be reduced to 85 mPa?s, and the viscosity reduction rate can reach more than 98%; meanwhile, the oil-water interfacial tension is reduced from 11.59 m/Nm to 0.06 m/Nm. The polymer has good temperature and salt resistance. After aging at 110℃ for 24 hours, the mineralization degreesalinity is 1.45?105 mg/L, and the viscosity reduction rate was more than 93%. At 50℃, 4.84?104 mg/L, the viscosity of polymer with mass fraction of 0.50% is 56 mPa?s, which is compared to the viscosity of the commercial partially hydrolyzed polyacrylamide solution 32 mPa?s. The polymer viscosity reducer has better aqueous thickening capabilities under mineralization conditions. The results of the flooding experiment show that the viscosity reducer flooding can increase the oil recovery by 37.45% on the basis of water flooding. The results show that the polymer solution can improve the recovery by reducing the heavy oil viscosity and expanding the sweep volume.