The　domain　decomposition　method　is　a　superior　method　in　solving　big　and　complicated　problem.　This　article　puts　forward　a　domain　decomposition　method　based　on　the　weighted　average,　this　method　decomposes　the　grid　based　on　the　land　cover,　and　discrete　parameters　using　time　dimension　finite　difference　method,　and　then　the　patches　of　each　grid　are　weighted　aggregated　to　obtain　the　final　output.　This　paper　proposed　the　concrete　steps　of　the　method,　and　validated　it　by　using　the　sensible　and　latent　heat　flux　simulation　result　based　on　the　CoLM　(The　common　land　model)　land　surface　model.　©　2012　IEEE.