This　paper　aims　at　enhancing　the　boiling　and　condensation　co-existing　phase　change　heat　transfer　process　inside　a　small　and　closed　space　by　heat-conduction　bridges.　The　working　fluid　is　deionized　water　and　the　copper　heat-conduction　bridges　are　machined　directly　on　the　boiling　surface　and　connect　the　boiling　and　the　condensation　surface.　Three　different　heat-conduction　bridges　that　are　all　rectangular　pillars　of　different　sizes　and　layouts　are　tested.　Experiments　were　carried　out　to　study　the　influences　of　working　fluid　filling　ratio,　the　cross　sectional　area　size　of　the　heat-conduction　bridge　and　the　gap　between　the　heat-conduction　bridges　(the　bridge　gap)　on　boiling　and　condensation　co-existing　heat　transfer　inside　the　small　and　closed　space.　Experimental　results　show　that　the　heat-conduction　bridges　can　greatly　enhance　the　boiling　and　condensation　co-existing　heat　transfer　process.　The　optimum　filling　ratio　is　50%　for　3　type　heat-conduction　bridges.　The　boiling,　condensation　and　overall　heat　transfer　coefficient　of　the　heat-conduction　bridges　whose　cross-sectional　area　is　2　mm　x　2　mm　and　bridge　gap　is　1　mm　(HCB-C)　is　the　largest　among　the　three　heat-conduction　bridges.　(C)　2017　Elsevier　Ltd.　All　rights　reserved.