Abstract: In the anaerobic membrane bioreactor (AnMBR), quorum sensing by microorganisms exacerbates biofouling, significantly hindering membrane performance and lifespan. Controlling the concentration of N-acyl homoserine lactones (AHLs) is crucial for membrane fouling control. This study used surface molecular imprinting technology, selecting furanone (DMHF) as a structural analog of AHLs and nano-magnetic Fe₃O₄ particles as the carriers. Using methacrylic acid (MAA) as a functional monomer, and azobisisobutyronitrile (AIBN) as the initiator, a magnetic molecularly imprinted polymer (DMHF/SMIP) with selective adsorption for DMHF was successfully prepared via surface polymerization. The DMHF/SMIP was characterized by using a Fourier transform infrared spectrometer (FTIR), scanning electron microscope (SEM), and vibrating sample magnetometer (VSM). These analyses indicated that the DMHF/SMIP, with a successfully encapsulated imprinting layer, exhibited a uniform particle size, stable crystal form, good superparamagnetism, and numerous surface imprinting cavities. These features enable the DMHF/SMIP to selectively bind to target molecules. Subsequently, the adsorption performance of DMHF/SMIP and its effect on membrane fouling control were evaluated. The results showed that DMHF/SMIP reached adsorption equilibrium in approximately 50 minutes, with a maximum adsorption capacity of 85.97 mg/g for DMHF. The adsorption process followed second-order kinetics and the Langmuir equation, suggesting primarily chemical and monolayer adsorption. This indicates that DMHF/SMIP has a high affinity for DMHF and can effectively remove it from the system. DMHF/SMIP exhibited excellent stability and recyclability, maintaining an adsorption efficiency of 83.01% even after five consecutive adsorption-desorption cycles. This demonstrates the material′s robustness and potential for long-term use. In selective adsorption experiments, DMHF/SMIP showed a high degree of selective recognition for DMHF and its structural analogs, with adsorption capacities of 24.09, 12.38, and 5.34 mg/g for DMHF, 4-methoxy-2,5-dimethyl-3(2H)-furanone (mesifurane), and 5-hydroxymethylfurfural, respectively. This selectivity is a key advantage of molecularly imprinted polymers, enabling the targeted removal of specific compounds from complex mixtures. Using DMHF/SMIP to adsorb representative AHLs (C₆-HSL), the adsorption capacity reached 3.93 μg/g. This suggests that the polymer can effectively capture AHLs, known to contribute to quorum sensing and biofouling. Finally, in the adsorption experiments, the removal rate of C₆-HSL by DMHF/SMIP reached 34.87%. This significant result demonstrates the polymer′s ability to reduce the levels of AHLs in AnMBR systems, potentially mitigating quorum sensing and biofouling. This study prepared a readily recyclable, magnetic molecularly imprinted polymer that selectively adsorbs AHLs, providing a theoretical basis and technical guidance for its application in water treatment. The development of such materials could revolutionize biofouling management in AnMBR systems, leading to more efficient and sustainable wastewater treatment.