The welded bracket is an important supporting component with the structural complexity and crucial functional roles in a large-scale agitator. Strength and modal analysis on it are carried out with the finite element analysis software COSMOS/DesignStar according to the equipment’s working behaviours in presence of rational FEA model of the welded bracket being created with 3D CAD software SolidWorks. The conclusion is made from analysis results that the strength criterion is satisfied with operating requirement of the equipment, and the risk area of the tensile stress is explored, moreover, the dangerous natural frequencies are 41Hz and 95Hz which are worked out respectively through modal analysis results. This analysis process is significant for the agitator design. The technique foundation and method are not only set up effectively, but also the utilized data is provided for the product design and successive manufacturing. The lead time of the agitator will be shortened, and the product quality will be improved.