Purpose. To examine the mediating role of positive psychological capital in the relationship between nursing students’ perceived social support and bullying behavior in nursing education. Design and Methods. In May 2021, a sample of 1196 nursing students majoring in nursing at a medical college was conveniently selected as the study population. A set of questionnaires, including a General Information Questionnaire, Perceived Social Support Scale (PSSS), Positive Psychological Capital Questionnaire (PPQ), and Bullying Behaviors in Nursing Education Scale (BBNE), were utilized to examine and analyze the relationships among the variables. Findings. The scores of nursing students’ PSSS, PPQ, and BBNE were 68.19 ± 11.90, 123.97 ± 18.74, and 13.31 ± 9.24, respectively. There was a negative correlation (r = −0.421, P<0.01) between perceived social support and bullying behaviors in nursing education among nursing students. Positive psychological capital partially mediated the relationship between perceived social support and bullying behaviors in nursing education, accounting for 19.88% of the total effect. Further analysis revealed that self-efficacy, resilience, optimism, and hope in positive psychological capital each played a partial mediating role in the impact of nursing students’ perceived social support on bullying behaviors in nursing education, with the ratio of indirect effect to total effect being 5.38%, 7.74%, 6.09%, and 5.34%, respectively. Practice Implications. The impact of perceived social support on bullying behaviors in nursing education is substantial among nursing students, and it can indirectly influence bullying behaviors through positive psychological capital. Nursing educators should pay attention to nursing students with lower levels of social support, and they can decrease the occurrence of bullying behaviors by enhancing social support and fostering higher levels of psychological capital.