Abstract: In order to study the effect of different setback methods on performance indexes and the reasonable setback methods of bundled-tube structure, the calculation models with different setback were designed. Mechanical characteristics of columns and spandrel beams of uniform vertical setback models were analyzed. Elastic-plastic mechanical performance of the structures such as elastic-plastic story drift, time of damage happen and energy dissipation were researched. The results show that the changing rule of the equivalent wind effect coefficient is the same as the base shearing force and base anti-overturning moment, and is considered as reference indicator before initial setback method is decided. The internal force of columns and spandrel beams show regular abrupt in the vertical setback location. The time history analysis results of models with uniform vertical setback show that the columns do not occur plastic damage; the spandrel beams occur plastic damage at different time. The energy dissipation values, at the time of plastic damage occurance are approximated.The location of the initial setback should be as far as possible from the embedded end. The reasonable setback method should be uniform.