Objective To explore the current situation and influencing factors of role breadth self-efficacy of nursing interns, and provide reference for implementing targeted intervention and improving the level of role breadth self-efficacy of nursing interns. Methods A total of 535 nursing interns from 5 hospitals in Hunan province were surveyed by using the general information questionnaire, the Role Breadth Self-Efficacy Scale and the Psychological Capital Scale. Results The total score of role breadth self-efficacy was （24.27±6.64） points, and the total score of psychological capital was （101.44±18.03） points.Hierarchical regression analysis showed that award-winning experience, the matching degree of hobbies and college major selection, hospital atmosphere, self-evaluation of adaptation in hospital and sensitive personality had influence on role breadth self-efficacy of nursing interns （all P＜0.05）; psychological capital alone could independently explain 31.5% of the total variation of role breadth self-efficacy. Conclusion Nursing interns have a high level of role breadth self-efficacy, which is influenced by many factors.Psychological capital can positively affect the role breadth self-efficacy of nursing interns.Teachers and nursing managers are suggested to take effective measures to improve psychological capital of nursing interns, so as to improve their role breadth self-efficacy, and finally stabilize and develop the nursing workforce.