This　article　proposes　a　novel　analytical　steady-state　thermal　simulation　framework　considering　anisotropic　thermal　conductivity　for　3-D　integrated　circuits　(3D-ICs)　that　combine　an　adaptive　rectangular　discretization　algorithm　with　a　conformal　meshing　strategy　to　achieve　enhanced　computational　efficiency　and　accuracy.　To　address　the　challenges　of　arbitrary　power　density　distributions　in　modern　3D-ICs,　we　develop　an　adaptive　rectangle　approximation　method　that　dynamically　adjusts　rectangular　partition　sizes　based　on　local　gradient　analysis　and　error-controlled　discretization　criteria.　The　derived　rectangular　thermal　sources　are　subsequently　processed　through　a　conformal　meshing　technique　that　preserves　geometric　fidelity　while　minimizing　mesh　complexity.　For　analytical　solution　derivation,　we　employ　the　domain　decomposition　method　effectively　to　divide　the　multilayer　3-D　structure　into　several　individual　layers　with　customized　general　solutions.　Interlayer　thermal　coupling　is　resolved　through　interfacial　boundary　condition　enforcement.　Numerical　simulations　demonstrate　that　the　proposed　analytical　thermal　method　achieves　significant　performance　improvements,　exhibiting　60×　acceleration　over　conventional　finite　element　method　(FEM)　implementations　while　maintaining　a　maximum　absolute　error　(MAX)　below　0.5　K　across　multiple　benchmark　cases　with　3D-ICs.　　©　IEEE.　1993-2012　IEEE.