Objective This study aims to prepare magnetic surface molecularly imprinted polymers (MMIPs) via a sol-gel method using tetracycline (TC) as the template molecule, and to combine them with spectrophotometry for the enrichment and detection of TC residues in fish meat.Methods Activated carbon (LAC) is prepared from Magnolia grandiflora seeds using 60% (w/w) phosphoric acid solution as the activator. Magnetic activated carbon (MLAC) is then obtained by co-precipitation-based magnetization of LAC. Using MLAC as the carrier and TC as the template molecule, MMIPs are synthesized, and their adsorption performance toward TC is investigated. The resulting materials are characterized by SEM, EDS, BET, and FTIR. After enrichment and separation by MMIPs, TC in fish meat is determined by spectrophotometry.Results At 298 K in a 600 mg/L TC solution, the MMIPs exhibit a maximum imprinting factor of 1.92, with an adsorption capacity of 108.18 mg/g. After six consecutive reuse cycles, the adsorption capacity of MMIPs remains at 76.46 mg/g, still reaching 69.23% of the initial adsorption capacity. The MMIPs also demonstrate strong adsorption selectivity toward substances with a fused tetracyclic ring structure. The adsorption of TC onto MMIPs follows pseudo-first-order kinetics and conforms to the Langmuir isotherm model, with an apparent constant n>1, indicating monolayer adsorption on a homogeneous solid surface. The thermodynamic parameter shows ΔH>0, suggesting that the adsorption is endothermic and favored at higher temperatures; ΔS>0, indicating an increase in system disorder; and ΔG<0, confirming that the adsorption process is spontaneous. At spiked concentration levels of 10~60 μg/mL, the recoveries range from 81.87% to 91.13%, with RSD values between 2.55% and 3.16%, demonstrating successful enrichment and detection of TC in fish meat.Conclusion The prepared MMIPs exhibit high adsorption capacity, good selectivity, and promising potential for practical applications.