• A novel extractant design method based on elements and chemical bonds is proposed, integrating knowledge-based molecular design to avoid combinatorial explosion.
• The method combines fuzzy comprehensive evaluation and analytic hierarchy process to rank extractant candidates based on multiple performance indices.
• Case study on benzene-cyclohexane separation demonstrates the method's effectiveness in identifying suitable extractants via quantum chemical analysis.
• The approach offers a systematic, efficient alternative to experimental screening and property constraint methods, with potential for industrial application.