Based on the electron bean circular weld on 2219 T852 transition ring and T87 shell section used for tank, the normal and low mechanical properties of the electron beam welded joints in the segment level were tested, and the staggered amount,fracture types and microstructure of the welded joints were analyzed. The following conclusions can be drawn.The normal and low strength effect coefficient of the segment level electron beam welded joints on 2219 T852 transition ring and T87 shell section are 0.63, and relative to the normal temperature, the low temperature mechanical properties of welded joints have been improved. The staggered amount is inversely proportional to the mechanical properties of welded joints,and it has the most significant effect to elongation, and low temperature should help to ease the weakening effect of staggered to the mechanical properties of welded joints. Because of the uneven tissue and the discontinuous structure of the electron beam welded joints,especially T852 side heat affected zone with coarse grains,the T852 side heat affected zone and the roots of welded joints are the weak area of the electron beam weld, and welded joint is easy to fracture in the area.