With　the　sharp　increase　of　very　large-scale　integrated　(VLSI)　circuit　density,　we　are　faced　with　many　knotty　issues.　Particularly　in　the　routing　phase　of　VLSI　physical　design,　the　interconnection　effects　directly　relate　to　the　final　performance　of　circuits.　However,　the　optimization　capability　of　traditional　rectilinear　architecture　is　limited;　thus,　both　academia　and　industry　have　been　devoted　to　nonrectilinear　architecture　in　recent　years,　especially　octilinear　architecture,　which　is　the　most　promising　because　it　can　greatly　improve　the　performance　of　modern　chips.　In　this　article,　we　design　FH-OAOS,　an　obstacle-avoiding　algorithm　in　octilinear　architecture,　by　constructing　an　obstacle-avoiding　the　octilinear　Steiner　minimal　tree　(OAOSMT).　Our　approach　first　constructs　an　obstacle-free　Euclidean　minimal　spanning　tree　(OFEMST)　on　the　given　pins　based　on　Delaunay　triangulation　(DT).　Then,　two　lookup　tables　about　OFEMST＇s　edge　are　generated,　which　can　be　seen　as　the　information　center　of　FH-OAOS　and　can　provide　information　support　for　algorithm　operation.　Next,　an　efficient　obstacle-avoiding　strategy　is　proposed　to　convert　the　OFEMST　into　an　obstacleavoiding　octilinear　Steiner　tree　(OAOST).　Finally,　the　generated　OAOST　is　refined　to　construct　the　final　OAOSMT　by　applying　three　effective　strategies.　Experimental　results　on　various　benchmarks　show　that　FH-OAOS　achieves　66.39　times　speedup　on　average,　while　the　average　wirelength　of　the　final　OAOSMT　is　only　0.36%　larger　than　the　best　existing　solution.　©　2016　ACM.