In this study, four geminal dicationic magnetic ionic liquids (GDMILs) functionalized with heterocycles and magnetic radicals were tailored for efficient tetracyclines (TCs) extraction via aqueous biphasic systems (ABS). The GDMIL-ABS achieved >98% efficiency within 5 minutes under solvent-free conditions, enabled magnetic separation, and maintained performance over five cycles. Phase behavior analysis indicated dependencies on GDMIL structure, temperature, and salt. The developed method was validated, obtaining excellent recoveries (98~103%) and satisfactory sensitivity with limits of detection (LOD) and quantitation (LOQ) in the ranges of 3.441~5.231 and 11.47~17.42 μg/L, respectively. Real environmental sample analysis confirmed good accuracy (92~98%) and high enrichment factors ranging from 112 to 229. Density functional theory (DFT) revealed extraction mechanism, demonstrating that the performance was primarily governed by TC-GDMIL binding energy and salting-out effect. This newly proposed GDMIL-ABS provides a simple and eco-friendly approach with significant potential for antibiotics extraction from aqueous solutions.