The　increasing　penetration　of　renewable　energy　(RE)　and　complex　interaction　of　energy　strengthen　the　necessity　of　energy　management　in　microgrid.　In　energy　management,　structure　and　loss　of　network　are　often　ignored　or　roughly　considered,　which　simplify　the　actual　operation　of　microgrid,　leading　to　the　low　practical　feasibility　of　scheduling　scheme.　This　paper　proposes　a　state　variables-based　two-stage　interval　optimization　method　of　combined　electric　and　heat　microgrid　considering　the　loss　and　uncertainties　of　RE　and　load.　Different　from　the　energy　hub　(EH)　model,　the　proposed　method　uses　network　topology　to　establish　an　optimization　model.　To　clarify　the　energy　distribution　of　microgrid　and　obtain　the　intervals　of　state　variables,　the　linear　model　of　microgrid　based　on　state　variables　is　developed.　Further,　network　loss　is　dynamically　integrated　into　the　model　to　accurately　reflect　the　actual　operation　status　of　microgrid.　Finally,　simulations　on　a　modified　33-node　Barry　Island　microgrid　are　conducted　to　verify　the　effectiveness　and　reliability　of　the　proposed　method　in　a　microgrid　with　high　penetration　of　RE.　©　2022　IEEE.