Abstract: Because of the great lifting force of tank shell to its bottom in the low-pressure storage tank, anchoring bolts often fastened to the outermost edge, which simutaneously considers the anti-earthquake requirements. The article presents the stress analysis of tank's shell, bottom plate and anchoring bolts for rigid foundation tanks such as concreate plate foundation. The derived theoretical calculating equations show that the old raw method has four obvious defects in the anchor design. The author compares his proposed calculating method with the old one, and comes to the conclusion that the simply supported force of anchoring bolts got from the old one is very conservative, the check-up of the combined section constituted with the edge plate, support plate and rib plate is also conservative.