Featured　Application:　The　pump-assisted　capillary　phase-change　loop　overcomes　the　two-phase　flow　instability　of　traditional　boiling　heat　dissipation　technologies.　Thus,　it　shows　prospects　for　use　in　the　heat　dissipation　of　electronics　devices　and　batteries　on　the　ground　and　in　space　in　applications　such　as　datacenter　cooling,　and　thermal　management　of　batteries　or　spacecraft.　To　overcome　the　two-phase　flow　instability　of　traditional　boiling　heat　dissipation　technologies,　a　porous　wick　was　used　for　liquid-vapor　isolation,　achieving　efficient　and　stable　boiling　heat　dissipation.　A　pump-assisted　capillary　phase-change　loop　with　methanol　as　the　working　medium　was　established　to　study　the　effect　of　liquid-vapor　pressure　difference　and　heating　power　on　its　start-up　and　steady-state　characteristics.　The　results　indicated　that　the　evaporator　undergoes　four　heat　transfer　modes,　including　flooded,　partially　flooded,　thin-film　evaporation,　and　overheating.　The　thin-film　evaporation　mode　was　the　most　efficient　with　the　shortest　start-up　period.　In　addition,　heat　transfer　modes　were　determined　by　the　liquid-vapor　pressure　difference　and　power.　The　heat　transfer　coefficient　significantly　improved　and　the　thermal　resistance　was　reduced　by　increasing　liquid-vapor　pressure　as　long　as　it　did　not　exceed　8　kPa.　However,　when　the　liquid-vapor　pressure　exceeded　8　kPa,　its　influence　on　the　heat　transfer　coefficient　weakened.　In　addition,　a　two-dimensional　heat　transfer　mode　distribution　diagram　concerning　both　liquid-vapor　pressure　difference　and　power　was　drawn　after　a　large　number　of　experiments.　During　an　engineering　application,　the　liquid-vapor　pressure　difference　can　be　controlled　to　maintain　efficient　thin-film　evaporation　in　order　to　achieve　the　optimum　heat　dissipation　effect.