For inner pressure tank, with the comparison of stress variation of pressure tank frames at two different forms of connection, the influence of different loading conditions on deformation and stress characteristics of the tank shell plate was analyzed. The results show that for different connection forms, the best angle β between the section changing location and the tank top plate exists with each form. In the circumferential range, different schemes mainly affect the tank top plate longitudinal stress and the circumferential stress of the frame and rib is affected by the β values.