Interpersonal relationship issues are one of the main factors affecting adolescent mental health, with peer-victimization attracting significant attention due to its widespread negative impact. This research investigates the impact of peer-victimization on psychological symptoms among high school students and assesses the moderating influence of teacher-student relationships. 337 high school students completed a questionnaire consisting of the Peer-Victimization Scale, the Teacher-Student Relationship Questionnaire, and the Chinese Adolescent Mental Health Scale. The results revealed that peer-victimization is significantly positively correlated with psychological symptoms in high school students. Furthermore, teacher-student relationships were found to weaken peer-victimization’s negative effect on psychological symptoms. When high school students under peer-victimization, a good teacher-student relationship can provide protection.