To　analysis　the　maximum　load　and　allowable　load　of　typical　pressure　bearing　structure,　confirm　the　load-bearing　capacity　of　pressure　vessels,　the　relationship　between　limit　load　of　structure　and　microscopic　character　of　typical　material　16MnR,　which　is　widely　used　in　pressure　vessels,　is　studied　in　this　paper.　Macro-trial　method,　Microscopic　observation,　Magnetic　memory　testing　and　FEM　are　used.　Metallic　materials-Charpy　notch　impact　test　is　done　to　inspect　the　sensitivity　of　the　impact　of　aging　at　ambient　temperatures,　and　the　results　show　that　16MnR　has　good　toughness　and　ductility.　There　are　five　kinds　of　pre-strain　state:　mother　metal,　5　percent,　10　percent,　15　percent　and　20　percent.　Tensile　test　of　long　board　with　two　side　holes　is　done,　metallographic　change　on　the　surface　is　observed　at　real　time,　and　magnetic　memory　method　is　used　to　discovery　inner　cracks.　In　the　end,　the　FEM　is　used　to　simulate　the　test　results.　Results　show　that　the　Akv　reduce　23.1　percent　when　the　pre-strain　reaches　to　15　percent,　but　still　above　150J;　the　limit　load　of　structure　and　the　microscopic　character　are　closely　connected,　when　the　deformation　looks　like　a　＇ravine＇,　the　structure　is　very　close　to　load　limits,　basically.　Finite　element　simulation　results　essentially　match　the　test　results;　in　the　practical　application　of　the　pressure　vessel,　there　is　still　great　tap　potentials　about　this　material.