The　paper　is　focused　on　the　working　mechanism　of　micro-heat　pipe　arrays　(MHPAs),　which　are　new　efficient　phase　transition　components.　The　three-dimensional　partition-minuteness　model　is　made　to　analyze　the　flow　and　heat　transfer　in　the　MHPAs　by　using　the　theory　of　two-phase　closed　thermosyphon　and　the　theory　of　condensation　on　vertical　walls　with　micro-channels.　The　surface　tension　is　considered　in　the　model.　Through　partitioning　the　condensate　on　the　surface　of　microchannels,　the　flow　and　heat　transfer　are　analyzed,　giving　the　thickness　of　condensate,　temperature　distribution　and　mass　flux.　The　Matlab　programs　based　on　the　three-dimensional　partition-minuteness　model　are　used.　The　calculation　results　agree　with　the　experimental　results.　The　error　is　within　5%.　The　formulas　for　the　saturation　temperature　in　the　condensation　part　of　the　MHPA　are　obtained　from　the　calculated　results.　©　All　Rights　Reserved.