Abstract: In order to improve the welding seam compactness of the box and reduce the problems of box welding seam whitening and residual bath liquid after sulfuric acid anodization, beginning with the structural characteristics of the aluminum alloy box, the friction stir welding structure design of the box, welding fixtures design and process parameter selection for welding and heat treatment, etc. are introduced in detail. Through the trial production and test verification of the sample, the tensile strength of the welded joint of the simulated product is more than 80% of that of the base metal and the welding seam can achieve 180° positive bending without cracks and fractures. At the same time, the box structure has also passed the test verification of the product. The structure design and process method of friction stir welding for sulfuric acid anodizing box have certain guiding significance for the manufacturing of this kind of products.