This study attempted to clarify the process of stress leading to suicidal thoughts through the MMPI-2-RF scale. The purpose of this study was to examine the mediation effect of anger tendency relationship between stress and suicidal thoughts, and the moderated mediation effect of relationship severance in this path. For this purpose, 1889 people aged 18 to 50 were measured through self-report surveys for stress, anger tendency, relationship severance, and suicidal thoughts. First, a significant correlation was found in all major variables. Second, the mediating effect of anger tendency was significant in the relationship between stress and suicidal thoughts. Third, relationship severance moderated the relationship between anger tendency and suicidal thoughts. Fourth, it was found that the mediating effect of anger tendency on the relationship between stress and suicidal thoughts was moderated by relationship severance. In other words, those with high relationship severance are less likely to experience suicidal thoughts through anger tendency, even if they experience stress. This study is meaningful in that it presents implications that are helpful for understanding and intervention of clients with a high level of stress in psychotherapy.