With　the　development　of　manufacturing　technology　and　process　level,　the　reliability　of　DC/DC　converter　becomes　higher　and　higher,　which　is　a　big　challenge　to　the　reliability　evaluation　of　DC/DC　converter.　In　this　paper,　to　solve　the　problem,　DC/DC　converter　is　studied　by　the　test　of　constant　electrical　stress　and　temperature　ramp　stress　method　(CETRM).　With　CETRM,　time　and　cost　of　the　test　are　efficiently　reduced.　Ten　DC/DC　converters　are　tested　using　CETRM.　Failure　sensitive　parameter,　activation　energy,　failure　temperature,　failure　rate,　lifetime　and　failure　rate　are　acquired,　which　testifies　the　application　and　efficiency　of　CETRM　for　DC/DC　converter　proposed　in　this　paper.　©　2011　IEEE.