Abstract: Based on the analysis of the domestic production of metal industry, the processing
of plate thickness of the tube metal structure is studied. The theory, method and steps of extracting
the interface geometry information are put forward. The accurate extraction of the interface
geometry information and the accurately processing of the plate thickness are realized by the
methods of diagram, analytical modeling and the system development based on the numerical
method. The method and steps can be used in similar cases. The research result can be applied to
improve product quality and reduce production cost of tube metal structure.

Key words: mechanical design, tube metal structure, processing the thickness of plate;
geometric information of interface