A　method　that　enables　rapid　determination　of　lifetime　for　semiconductor　devices　based　on　the　study　of　process-stress　accelerated　life　test　is　presented,　and　the　theory　model　is　constructed.　To　demonstrate　the　application　of　the　method,　3CG120　a　kind　of　mature　products,　has　been　used　as　a　sample　for　test.　A　process-stress　accelerated　test　was　conducted　in　the　temperature　range　from　175°C　to　345°C　to　rapidly　extract　the　data　of　relationship　between　temperature　and　the　degradation　of　sensitive　parameters,　and　the　temperature　characteristics　and　degenerating　characteristics　of　sensitive　parameters　under　electrical　stress　of　the　specimens　were　acquired.　Then　the　related　reliable　parameters,　such　as　activation　energy　and　lifetime　were　figured　out　by　utilizing　the　model.　The　results　of　experiments　are　in　agreement　with　literature,　which　proves　that　the　method　is　feasible.