Background: Nursing students face a lot of complicated situations and problems when they participate in psychiatric clinical practice for the first time. However, the nursing students' internship experience and career intention in psychiatry have not been well described in China. Purpose: This study aims to explore the experience and career intention of Chinese nursing undergraduates during their first psychiatric internship. Method: This is a qualitative design using phenomenological approach. Data were collected through a case-study, semi-structured, two face-to-face in-depth interviews (N = 13) with third-year nursing students from a university in China on their first clinical internship in a psychiatric department. We followed the consolidated criteria for reporting qualitative research (COREQ) checklist. Results: Four themes were identified: negative stereotype perceptions about mental illness, professional maturation, personal development, attitude towards psychiatric patients and career choice. Conclusions: The experience of nursing students in psychiatric clinical practice was constantly changing. This study indicated that nursing students went through a continuous development process of psychiatric care professional maturation and personal development. However, psychiatric nursing was not an ideal career choice of nursing students. This study provides guidance for educators to optimize the internship experience and take comprehensive measures to improve the professional attractiveness and professional identity of psychiatric nursing.