Based　on　the　mechanism　of　physical　memory　effects,　an　improved　fractional　Zener　constitutive　model　is　proposed　to　describe　the　boundary　layer　characteristics　of　viscoelastic　fluids　in　magnetohydrodynamic　(MHD)　environments.　The　model　employs　a　mixed-order　structure　where　instantaneous　elastic　response　maintains　integer-order　characteristics,　while　delayed　elastic　response　and　viscous　flow　introduce　fractional　operators.　This　design　simultaneously　captures　the　stress　relaxation　and　strain　lag　characteristics　of　the　fluid.　The　established　model　is　numerically　solved　using　the　finite　difference　method　together　with　a　fast　algorithm,　and　the　regulatory　mechanisms　on　the　fluid　boundary　layer　characteristics　are　investigated.　The　research　reveals　that　the　proposed　model　achieves　more　comprehensive　characterization　of　boundary　layer　behavior　compared　to　conventional　models,　while　exhibiting　unique　saturation　effects　in　magnetic　field　regulation.　The　fractional　parameter　α　governs　stress　relaxation,　with　larger　values　enhancing　viscous　behavior　and　producing　thicker　boundary　layers.　Parameter　β　controls　strain　memory　intensity,　promoting　greater　flow　mobility.　Rheologically,　a　larger　stress　relaxation　time　λ1　enhances　elastic　character　and　compacts　boundary　layers,　while　an　increased　strain　lag　time　λ2　extends　microstructural　adjustment　time,　manifesting　as　thicker　boundary　layers.　This　study　establishes　correlations　between　model　parameters　and　physical　phenomena,　providing　a　theoretical　framework　for　understanding　MHD　viscoelastic　fluid　boundary　layer　behavior.　©　2025　Author(s).