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Fatigue is the main failure mode of engine's complicated components like cylinder heads.Hence,an accurate life model would help direct anti-fatigue methods.However,because cylinder heads undergo complex thermal and mechanical loadings,it would be very difficult to conduct tests which can completely simulate the thermo-mechanical fatigue condition.In this study,in order to evaluate the fatigue time of cylinder heads with high efficiency,since cylinder heads' lifetimes are decided by the low cycle fatigue areas on its fire deck,this critical location should be highlighted.A near-components-shaped specimen “valve bridge sample” were designed and then tested on a one-way pull-press fatigue machine.By comparing the measured fatigue lifetimes from tests to the calculated ones from four life prediction formulas,a preferable formula was selected to establish the original lifetime model.Then,taking into account that material related parameters like yield limit would decrease under high temperature,the original lifetime model was corrected by adopting the temperature factor “t”.Finally,the availability and accuracy of the life model were validated.