Abstract: The three-dimensional finite element method is used to analyze the stress of crescent-rib bifurcation with waistline turning angle of zero degree and the influence of waistline turning angle on the stress of the wall and crescent-rib of bifurcation. The results indicate that waistline turning angle has little effect on the stress of the crescent-rib. The design scheme with waistline turning angle of zero degree reduces the stress in the obtuse angle area and improves the stress of the bifurcation. Keeping the wall thickness of basic cone unchanged,the ability of bifurcation to bear internal pressure can be improved by increasing the wall thickness of transition pipe. Because the waistlines of the main cone pipe and the branch cone pipe are collinear,the fabricating difficulty and error can be appropriately reduced during assembly,which can be used in engineering design.