The steel frame-bent structure is the main load-supporting structure in thermal power plants of China,whose structural quality and rigidity are distributed non-uniformly. It is particularly necessary to research earthquakeresistant behavior of this structure. The time history response analysis method was used to study the dynamicproperties, the interlayer deformation and the interlayer shear of steel frame-bent structures of main buildings for largethermal power plant. The results showed that there were many weak parts in the horizontal frame-bent and longitudinalframe-supporting structures, which must be strengthened when designed. The space model should be used to considerthe effect of torsion in structural calculation and analysis.