The invention provides a crimping structure with the series connection of thyristors of multiple stages. An external frame of the crimping structure is formed by two insulating pull rings and a left yoke and a right yoke connected to the two insulating pull rings. A silicon stack unit is formed by the series connection of multiple heat radiators and multiple thyristors alternately. The silicon stack unit is installed between the left yoke and the right yoke through a pressure unit arranged at one end. The insulating pull rings can provide pressing force with a larger range than that of an existing tensioning device, the good contact between the thyristors and the heat radiators is ensured, thus the thyristors get good heat dissipation effect and through-flow effect, the press mounting requirements of thyristors with larger sizes and more stages can be satisfied. The crimping structure of the present invention has the advantages of compactness, a small number of components, simple assembly and convenient maintenance.