A　numerical　investigation　is　performed　to　study　the　flow　and　heat　transfer　characteristics　in　a　microchannel　with　droplet　reentrant　cavities,　which　have　different　angles　with　equal　diameter　section.　The　thermal　enhancement　factor　(η)　and　augmentation　entropy　generation　number　(Ns,a)　are　used　to　evaluate　the　comprehensive　performance　of　the　microchannel.　The　numerical　results　indicate　that　the　pressure　drop　of　microchannel　with　droplet　reentrant　cavities　reduced　zigzag　along　the　flow　direction.　Compared　with　the　rectangular　microchannel,　the　droplet　reentrant　cavities　have　less　effect　on　the　pressure　drop.　When　Re　is　small,　the　effect　of　droplet　reentrant　cavities　on　heat　transfer　increases　little　and　even　less　than　rectangular.　However,　when　Re＞300,　as　the　angle　between　export　tangent　of　reentrant　cavity　and　equal　diameter　section　decreases,　the　heat　transfer　performance　gradually　increases.　The　analysis　of　entropy　generation　show　that　the　irreversible　loss　caused　by　heat　transfer　increases　with　the　Reynolds　number,　but　the　irreversible　loss　caused　by　flow　friction　decreases,　and　heat　transfer　entropy　generation　is　the　major　component　of　the　total　entropy　generation.　The　irreversible　loss　of　microchannel　with　droplet　reentrant　cavities　is　smaller　than　the　rectangular　channel　and　the　smaller　of　angle　with　equal　diameter　section,　the　less　of　the　irreversible　loss.　©　2017　Journal　of　Mechanical　Engineering.