Composite extractant and Fischer-Tropsch synthesis distillate oil separation method using same

The invention relates to the technical field of chemical separation, in particular to a composite extraction agent and a method for synchronously removing oxygen-containing compounds and aromatic hydrocarbons in high-temperature Fischer-Tropsch synthesis distillate oil by using the extraction agent. Aiming at high-temperature Fischer-Tropsch synthesis distillate oil, the invention develops a composite extraction agent for removing oxygen-containing compounds and aromatic hydrocarbons in oil together and an extraction process, and the extraction agent is composed of a main solvent, a cosolvent, a modifier and a polymerization inhibitor. High-temperature Fischer-Tropsch synthesis distillate oil is subjected to unit treatment such as liquid-liquid extraction, extraction phase back extraction, extraction agent and back extraction agent regeneration, oxygen-containing compounds and aromatic hydrocarbons in the distillate oil are removed together, and the back extraction agent is C5-C7 hydrocarbon compounds. Compar