This paper developed design software combined with Germany DIN 18800 standard, based on ANSYS. The influences of construction quality and stiffening rib on the shell’s design stress were investigated by means of buckling theory, based on a practical project. The results show that the difference of construction quality can greatly change the design stress of thin-walled cylindrical shell. And the reasonable spacing of stiffening rib can make the critical stress get better play in the shell’s stability analysis.