In　order　to　detect　the　MOSFET　junction　temperature,　the　paper　measures　the　MOSFET　junction　temperature　by　electrical　method　without　affecting　the　normal　operation　of　the　devices　and　the　circuits.　In　addition,　the　method　of　optimizing　the　temperature　calibration　curve　proposed　is　helpful　for　engineers　to　efficiently　monitor　the　junction　temperature　and　prevent　the　risk　of　failure　caused　by　high　temperature.　©　2019　IOP　Publishing　Ltd.　All　rights　reserved.