Major trauma is defined as a significant injury or injury that has the potential to be life-threatening and is quantitatively identified as an injury severity score (ISS) >15. Spinal injuries are common in patients with major trauma; however, because spinal injury is not independently included in the ISS calculation, the impact of spinal injury on mortality in patients with major trauma has not been fully elucidated. The purpose of this study is to identify the association between spinal injury and mortality in patients with major trauma. From January 1, 2016, to December 31, 2020, retrospective analysis was conducted on 2893 major trauma adult patients admitted to a level 1 trauma center. There were 781 patients in the spinal injury group and 2112 patients in the group without spinal injury. After matching the 2 groups 1:1, we compared injury mechanism, mortality, cause of death, intensive care unit length of stay (ICU LOS), and duration of ventilator use between spinal injury group and matched cohorts. Falls and traffic accidents were the most common injury mechanisms in the spinal injury group and the matched cohort, respectively. The mortality was significantly lower in the spinal injury group compared with the matched cohort (4.0% vs 7.9%, P =.001), and the ICU LOS was longer than the matched cohort (8.8 ± 17.4 days vs 7.2 ± 11.7 days, P =.028). In the spinal injury group, multiple organ failure (MOF) was the most common cause of death (41.9%), while that in the matched cohort was central nervous system (CNS) damage (61.3%). In patients with major trauma, spinal injury may act as a shock absorber for internal organs, which is thought to lower the mortality rate.