The cationic SBR latex, jointly developed with Dalian University of Technology, is a stable emulsion formed by polymerization of butadiene and styrene. It excels in adhesion, stability and liquidity. It is an emulsion polymer specially used for modified emulsified asphalt, which is synthesized by appropriately adjusting the polymerization process according to the characteristics of asphalt. When SBR latex is applied to modify emulsified asphalt, it can reduce the temperature sensitivity of asphalt and has a good elasticity performance. It can increase the low-temperature ductility of asphalt and has better high-temperature performance. It is easy to use and has excellent performance.