Objective To introduce the positive experience of student nurses during clinical internship of psychiatric nursing and to analyze the influencing factors. Methods An anonymous questionnaire survey was conducted for 128 student nurses who completed the clinical internship of psychiatric nursing. The questionnaire consisted of 8 domains with 32 items. Results The differences of scores of training group (P<0.05) and interest in psychiatric nursing (P<0.01) of undergraduate student nurses and college student nurses were statistically significant. Eight domains of positive experience were significantly correlated with each other. The results of multiple regression analysis showed that interaction with patients and nursing practice were major factors that influenced the overall evaluation and interest in psychiatric nursing. Interest in psychiatric nursing was also influenced by clinical instructing and teaching and educational level. Conclusion The positive experience of student nurses during clinical internship is affected by various factors. Psychiatric nursing education should focus on communication skills and understanding patients. Teachers should involve in practice guidance and play an active role in exerting positive affects on student nurses.