Abstract: A plug flow reactor was used to prepare high impact acrylonitrile-butadiene-styrene copolymer (ABS) resin by continuous bulk polymerization. The effect of microstructure, the viscosity of the solution, the type of composition of the rubber on the impact strength of ABS resin was investigated. The optimized toughening system was found. When the feed ratio of the rubber was 9.0 % and the synthetic adhesive ratio was 55AE∶35AE=2∶1, the Izod notched impact strength of the samples was 351.3 J/m, which was better than that of marketed products.