This study examined how normative beliefs, identification scores, perceived severity, self-efficacy in intervention, and victim-blaming tendencies impact teachers' willingness to intervene in relational bullying. Two groups of Taiwanese teachers (145 and 541 participants) completed self-developed questionnaires. Reliability and validity were assessed using Rasch analysis for the first group, while the second group's data were analyzed through hierarchical multiple regression. The results indicated that normative beliefs, perceived severity, victim-blaming tendencies, and self-efficacy significantly predicted teachers' willingness to intervene. Additionally, victim-blaming tendencies moderated the relationship between intervention efficacy and willingness. Specifically, under conditions of low self-efficacy, a high victim-blaming tendency led to a significantly reduced willingness to intervene. This study underscores the importance of improving teachers' awareness and skills in addressing relational bullying.