This　paper　introduces　a　parallel　electromagnetic　(EM)　optimization　method　using　neuro-transfer　function　(neuro-TF)　surrogate　and　isomorphic　orthogonal　Design　of　Experiments　(DOE)　sampling　for　microwave　filter　design.　A　sampling　strategy　that　combines　isomorphic　orthogonal　DOE　with　parallel　EM　simulations　is　employed　to　generate　training　data　for　the　neuro-TF　surrogate.　This　sampling　strategy　ensures　a　scattered　distribution,　thereby　enhancing　the　accuracy　of　the　surrogate　model　and　speeding　up　the　optimization　process.　Using　adaptive　splitting,　a　poleresidue　tracking　technique　adjusts　based　on　neighboring　sample　data,　improving　the　continuity　and　precision　of　the　surrogate＇s　pole-residue　representation.　This　approach　results　in　faster　and　more　efficient　optimal　solutions　with　fewer　iterations,　as　demonstrated　in　an　example　of　EM　optimization　for　a　microwave　filter.　　©　2024　IEEE.