Abstract: We addressed the design and service-lifetime evaluation of the large-sized rupture disc made of 316 L stainless-steel,a key disposable component of the overpressure protection device installed inside one of the vacuum vessels of China Fusion Engineering Test Reactor(CFETR).The leakage-induced blow-up of the dome-shaped rupture disc was empirically approximated,mathematically modeled and numerically simulated in finite element method for design optimization.The influence of the disc thickness,fillet radius and seam width on the blow-up behavior of the rupture disc was investigated for design optimization.In addition,the fatigue life of the optimized rapture disc was numerically analyzed with Fatigue Tool and Code DesignLife software.The fatigue analysis results show that the rupture disc meets the design requirements and may enjoy a service lifetime longer than 40 years.