©,　2015,　Xi＇an　High　Voltage　Apparatus　Research　Institute.　All　right　reserved.Base　on　the　similarity　of　electric　field　and　temperature　field,　the　heat　charge　simulation　method　was　given　to　calculate　the　composite　dielectric　steady　temperature　field　for　underground　cables.　In　this　paper,　the　cable　was　equivalent　to　two　layers.　Using　the　calculation　method　of　composite　dielectric　electrostatic　field　for　reference,　we　introduce　the　concept　of　bound　heat　charge　according　to　the　bound　charge.　Based　on　uniqueness　principle　of　field,　steady　temperature　of　buried　cable　was　calculated　by　heat　charge　simulation　method.　The　graphs　of　temperature　field　and　heat　quantity　were　given.　The　test　and　finite　element　method(FEM)　simulation　have　proved　that　heat　charge　simulation　method　is　effective　to　calculate　the　steady　temperature　field　of　underground　cables.