Evaporation　from　nanoporous　membranes　is　an　emerging　and　efficient　thermal　management　strategy　for　microelectronic　devices,　and　its　mechanism　has　been　extensively　studied.　It　has　been　found　that　there　are　many　factors　that　affect　the　evaporation　rate,　such　as　porosity　and　meniscus.　In　this　paper,　the　equivalent　evaporation　coefficient　is　introduced　to　account　for　all　these　factors　to　transform　the　nanopore　evaporation　into　one-dimensional　plane　evaporation　so　that　the　evaporation　flux　from　any　nanopore　configuration　can　be　simply　solved.　Theoretical　analysis　and　modeling　are　performed,　and　direct　simulation　Monte　Carlo　(DSMC)　method　is　used　to　verify　the　reliability　of　the　model.　The　proposed　equivalent　evaporation　coefficient　incorporates　the　meniscus　shape,　nanopore　transmissivity,　nanopore　porosity,　and　the　intrinsic　evaporation　coefficient　with　solid　physical　sounds.　The　overall　accuracy　of　our　model　is　excellent,　with　94.5%　of　simulated　data　being　predicted　within　5%.　The　physical　meaning　of　the　equivalent　evaporation　coefficient　presented　in　this　paper　is　clear　and　comprehensive,　which　significantly　facilitates　engineering　application.