In　this　paper,　the　air-side　channels　in　the　plate-fin　radiator　are　simulated　for　the　serrated　fins　in　the　plate-fin　heat　sink.　The　Nusselt　number　of　the　fins　under　different　Reynolds　numbers,　the　relationship　between　the　surface　heat　transfer　factor,　resistance　factor　and　the　Reynolds　number　are　calculated.　The　numerical　simulation　results　are　compared　with　the　relevant　literature　empirical　values　and　empirical　formulas.　The　calculation　results　show　that　with　the　increase　of　Re　number,　the　Nusselt　number,　convective　heat　transfer　coefficient　and　pressure　drop　of　the　heat　sink　increase　with　each　other;　the　heat　transfer　factor　and　the　resistance　factor　increase　with　the　Reynolds　number　go　down　which　can　guide　the　determination　of　the　size　of　the　plate　fin　radiator.