Pyrolysis gasoline from ethylene cracker undergoes pre-fractionation to remove C₅ and lighter components and C₉⁺ components, and then undergoes two-stage hydrogenation to hydrogenate olefins into saturated hydrocarbons and remove impurities such as sulfur, nitrogen and oxygen to obtain hydrogenated pyrolysis gasoline. The hydrogenated pyrolysis gasoline is separated by BTX extraction and distillation to obtain products such as benzene, toluene and mixed xylene. In this paper, the technological route and operation key points of BTX aromatics extraction unit with hydrogenated pyrolysis gasoline as the feed are analyzed. It differs from the traditional aromatics extraction in the introduction of raffinate extraction system and water washing coupling process, which recovers benzene from non-aromatic hydrocarbons and removes solvents from non-aromatic hydrocarbons. The technical problem of separating C₈ non-aromatics from aromatics in BTX extraction can be solved, and the solvent quality deterioration caused by the accumulation of heavy components can be solved by the coupling process. The two separation columns of toluene, mixed xylene and heavy aromatics in the aromatics distillation system are integrated into a single column to obtain on-spec toluene and mixed xylene products.