Direct　electromagnetic　(EM)　optimization　for　microwave　components　design　is　usually　a　time-consuming　process.　To　improve　the　optimization　efficiency,　this　paper　proposes　a　novel　parallel　EM　optimization　technique　exploiting　improved　pole-residue-based　neuro-transfer　function　(neuro-TF)　surrogate　and　isomorphic　orthogonal　design　of　experiment　(DOE)　sampling　strategy.　We　propose　a　new　sampling　method　combining　isomorphic　orthogonal　DOE　and　parallel　EM　simulations　to　generate　training　data　for　developing　the　neuro-TF　surrogate.　This　proposed　sampling　method　can　ensure　the　scattered　distribution　of　data　samples　in　the　overall　optimization　process,　thus　effectively　improving　the　surrogate　accuracy　and　increasing　the　optimization　speed.　We　also　propose　a　new　pole-residue　tracking　technique　for　order-changing　to　solve　the　discontinuity　problem　of　pole/residues　during　the　neuro-TF　surrogate　development.　Different　from　the　fixed　split　ratio　in　existing　pole-residue　tracking　technique,　the　split　ratio　of　poles　and　residues　in　the　proposed　technique　is　adaptive　and　determined　according　to　the　information　of　neighboring　samples.　Therefore,　the　continuity　and　smoothness　of　pole/residues　after　the　splitting　are　improved,　so　as　the　neuro-TF　surrogate　accuracy.　In　addition,　the　trust　region　algorithm　is　exploited　during　EM　optimization　to　improve　the　convergence　speed.　In　this　way,　the　proposed　EM　optimization　technique　obtains　the　optimal　solution　in　a　shorter　time　with　fewer　iterations　than　the　existing　techniques.　Two　examples　of　EM　optimizations　of　microwave　components　are　used　to　illustrate　the　proposed　technique.