With　the　vertical　stacking　of　circuit　layers,　the　power　density　of　3D-IC　increases　exponentially.　Interlayer　liquid　cooling　is　a　promising　and　scalable　solution　for　high　heat　flux　removal　in　3D-IC　(three-dimensional　integration　circuit).　The　flow　and　heat　transfer　performances　of　water　through　uniform　and　double-side　heat　flux　3D-IC　of　interlayer　in-line　micro-pin　fins　structure　with　heat　transfer　areas　of　1　cm2　and　Reynolds　number　ranging　from　150　to　900　were　studied　numerically.　3D-IC　with　in-line　micro-pin　fins　for　pitches　of　200　μm,　diameter　of　100　μm　and　heights　of　200　μm　was　analyzed.　Results　show　that　interlayer　liquid　cooling　of　3D-IC　with　in-line　micro-pin　fins　has　better　heat　exchange　effect　than　that　with　rectangular　micro-channels.　For　the　Reynolds　number　of　770,　the　power　reaches　to　250　W,　which　is　equivalent　to　8.3　kW/cm3　volumetric　heat.　Compared　with　rectangular　micro-channels,　the　average　temperature　and　the　maximal　junction　temperature　of　the　heater　surface　with　in-line　micro-pin　fins　are　only　46.34,　13.96　K,　down　by　13.26,　21.34　K,　respectively.　©　2017,　Editorial　Department　of　Journal　of　Aerospace　Power.　All　right　reserved.