This study examined the sequential mediating effects of social support and emotion dysregulation in the pathway from the world assumptions to posttraumatic stress symptoms after suffering intimate partner violence. Considering the bidirectional relationship, the alternative model was established to verify the sequential mediating effects of the world assumptions and emotion dysregulation in the relationship between social support and posttraumatic stress symptoms. For this study, a total of 134 college students (77 males, 57 females) completed questionnaires through online survey. As a result, there were significant sequential mediating effects of social support and emotion dysregulation in the relationship between world assumptions and posttraumatic stress symptoms. In other words, individuals with lower positive world assumptions showed lower perceived social support, higher levels of emotion regulation difficulties, and higher levels of posttraumatic stress symptoms. Furthermore, the sequential mediating effects of an alternative model were also significant, supporting the bidirectional relationship between world assumptions and social support. Finally, implications and limitations of the study were discussed.