Steel structure processing map is basis for components processing in steel structure processing plants. At present, dimensioning of processing map mainly relies on manual adjustments, which occupy more than 50% of detail design workload. Automatic dimensioning can improve the efficiency of the generation of processing map. Template-based automatic dimensioning technology of steel structure processing map is researched and the structure of automatic dimensioning template is analyzed through the dimensioning characteristics of processing map. The content of automatic dimensioning template is divided into five parts: component type management, view type management, dimensioning direction determination, dimensioning point selection, and dimensioning line style management. The design method of automatic dimensioning template is analyzed by the applications in Advance Steel and dimensioning plug-in of Tekla. The processing maps generated by customized dimensioning template meet the design requirement, with no need for manual adjustments.