A batch of reinforced concrete rack structure industrial buildings built in the 1950s still exists in large quantities in China, and some of the buildings still undertake important production tasks. The original design of these buildings has a low seismic defence standard, a long service life, and a high difficulty in toughness upgrading. In order to explore the effective method of toughness enhancement of existing reinforced concrete rack-structured industrial buildings under seismic action, a horizontal 3-span rack-structured factory building is selected as the research object, and two toughness enhancement methods are proposed, which are the addition of anti-flexural restraint bracing between columns (seismic damping) and seismic damping between columns and seismic isolation at the top of columns of the racks (integration of seismic damping and isolation). Twenty seismic waves were selected to carry out incremental dynamic analysis of the plant structure before and after toughness upgrading, and the effect of the two methods of damping and isolation integration on the toughness upgrading of industrial plants was evaluated by comparing the seismic vulnerability of the plant structure. The results show that both damping and compartmentalisation can effectively improve the seismic toughness of industrial buildings. For industrial building structures with damage to the substructure, damping is the most obvious method to improve the seismic toughness of the building structure, and for industrial building structures with obvious weak zones in the roof, it is more appropriate to use compartmentalisation.