The　traditional　interval　energy　flow　algorithm　of　integrated　energy　system　(IES)　can　only　analyze　the　results　of　the　combined　action　of　multiple　uncertainty　factors,　but　fails　to　quantify　the　transmission　process　of　each　uncertainty　factor　and　its　influence　on　the　system　state　variables.　To　deal　with　this　issue,　a　system　uncertainty　model　based　on　affine　arithmetic　is　established　and　an　affine　multi-energy　flow　algorithm　for　integrated　heat　and　electricity　system　(IHES)　is　proposed　in　this　paper.　First,　an　affine　temperature　transmission　model　is　established　based　on　the　temperature　exponential　equation　simplified　by　Taylor　expansion,　and　further　an　affine　model　of　the　IHES　is　established　considering　the　uncertainty　of　the　conversion　efficiency　of　the　coupling　elements.　On　this　basis,　considering　the　pipeline　flow　constraint,　the　heat　network　affine　energy　flow　algorithm　based　on　Back/Forward　sweep　method　is　proposed.　Furthermore,　the　parallel　iteration　method　for　the　affine　energy　flow　of　the　IHES　is　proposed　by　taking　the　coupling　element　power　as　the　boundary　condition.　Finally,　based　on　the　IEEE-33　system　and　23-node　heat　network　systems,　the　conservative　advantages　of　the　proposed　method　are　verified;　and　the　degree　of　influence　of　different　node　load　variation　on　mass　flow　rate　and　temperature,　and　the　interaction　effects　between　subsystems　are　analyzed.　©2023　Chin.Soc.for　Elec.Eng.