In order to improve the rollover crashworthiness of coach, three roof beam structures commonly used in coach were established with finite element models for the rollover simulation, then the energy absorption, acceleration and body pillar deformation were analyzed. The simulation results show that circle-curved transition and non-curved transition on the roof have better collision performance. Especially, the latter not only reduces the acceleration peak value, but also transfers more collision energy to the offside lateral. The whole coach body will be involved in deformation, thus, the intrusion of survival space would be reduced. Finally, the complete vehicle skeleton finite element model of a 6127-type high-bed coach was built, and the influences of circle-curved transition and non-curved transition on the roof in rollover test were analyzed.