In order to study the crashworthiness and occupant-protecting ability of tram car under side impact accident, a 5-module 100% low-floor tram car with dummy and a 6120 bus FEM models were established. By designing the impact scenario that a low-floor tram car parking on the rail impacted perpendicularly on the side faces of floating module by a bus with the velocity of 30 km/h and simulating the whole process of crash in LS-DYNA. It was shown that deformation was generated and occupant on the impacted side was pushed off the chair in designed scenario due to the impact force, which also caused the whiplash injury of occupant without neck protection. Designing guard bar in sidewall, separate seat from sidewall and install headrest and seatbelt will improve the crashworthiness of tram car and decrease injury criterion and provide occupants a safer ride environment.