Abstract: A complete set of process for extractive distillation of styrene from pyrolysis gasoline（STED） was developed. It was the first time to recover high purity styrene from pyrolysis gasoline，and at the same time to save hydrogen and to reduce carbon dioxide emission. The whole set of STED process includes composite solvent with high selectivity and strong polymerization inhibition，combined solvent regeneration of extraction and stripping，quality control of extractive distillation process，and efficient decolorization of styrene. The whole set of STED process has realized long-term stable operation in 7 sets of units，and all parameters meet the design requirements. The calibration results of a 27 kt/a STED industrial unit show that the purity of styrene product is 99.92%，and the platinum cobalt chroma is less than 10 which meets the national quality standard, and the recovery rate of the whole process is 95.8%.

Key words: pyrolysis gasoline, extractive distillation, styrene