This　paper　presents　a　design　and　optimization　method　of　bandpass　filters　based　on　space　mapping　technique.　The　geometric　parameters　of　the　filter　are　optimized　by　updating　two　models　(the　iteration　of　the　coarse　model　and　the　fine　model).　The　fine　model　is　obtained　by　the　electromagnetic　(EM)　simulation　software　HFSS,　and　this　model　is　used　to　simulate　the　accurate　frequency　response　of　the　bandpass　filter.　The　coarse　model　is　founded　by　ADS,　which　is　based　on　circuit　theory　and　used　to　match　the　response　of　the　fine　model　and　compare　it　with　the　ideal　filter　model.　A　traditional　waveguide　bandpass　filter　was　designed　and　optimized　to　confirm　this　method.　Experimental　results　demonstrate　the　efficacy　of　the　method.　©　2023　Applied　Computational　Electromagnetics　Society　(ACES).