Abstract: The ABS resin with a low content of volatile organic compounds (VOC) was prepared by a supercritical extraction process and its preparation process was investigated. The effects of three types of chain transfer agents including dodecyl mercaptan,α-methylstyrene linear dimer and Methyl 3-mercaptopropionate on the total VOC content were also investigated. The results indicated that the ABS resin prepared with α-methylstyrene linear dimer had the lowest TVOC content, and the optimum amount of this linear dimer used for ABS resin is equal to 3.5 times of the amount of dodecyl mercaptan. A four-factor orthogonal design was conducted with extrusion temperature, residence time, vacuum degree, and the optimum amount of extracting agent, and the optimum process conditions was determined as a extrusion temperature of 250 ℃, a residence time of 1 min, a vacuum degree of 0.99, and the amount of extracting agent CO2 of 1.5 wt% corresponding to the yield of ABS resin.