For　obtaining　fatigue　limit　and　dealing　with　censored　data,　the　＇pair-life-weighted＇　and　＇censored　life　approximation＇　methods　were　proposed.　According　to　the　fatigue　testing　of　TA15　electron　beam　welded　specimens,　conventional　methods　and　two　methods　in　this　article　were　used　separately　to　calculate　the　fatigue　limit　and　lognormal　distribution　parameters　of　the　lives　at　different　stress　levels,　and　C-P-S-N　curves　were　obtained　and　their　corresponding　mathematical　expressions　of　12　groups　under　2　confidence　and　6　reliability　were　expressed　as　a　three-parameter　model.　The　results　show　that　the　＇pair-life-weighted　method＇　is　in　good　agreement　with　the　traditional　method,　when　the　lives　have　a　difference　of　3　times　at　the　same　stress,　the　fatigue　limit　only　have　a　difference　of　0.5%,　it　is　the　further　evidence　of　the　practicability　in　engineering　about　the　traditional　method　;　And　the　relative　error　of　＇censored　life　approximation＇　and　conventional　method　is　less　than　1%　in　the　life　of　N＞106　cycles;　The　confidence　mainly　affects　the　short-lived　areas　of　fatigue　curve,　when　N≥106　cycles,　the　stress　error　determined　by　90%　and　50%　confidence　level　two　curves　is　less　than　4.5%.