Objective To explore the mediating role of professional self-concept in the relationship between future time perspective and career decision-making self-efficacy among master of nursing students, so as to provide a reference for nursing educators taking targeted measures to improve their career decision-making self-efficacy. Methods Totally 328 master of nursing students from 25 universities were recruited by using convenience sampling, then they were investigated utilizing a general information questionnaire, the Career Decision-making Self-efficacy Scale, the General Future Time Perspective Questionnaire and the Nursing Professional Self-concept Scale. Results The students′ scores of career decision-making self-efficacy, professional self-concept and future time perspective were (3.32±0.64), (2.70±0.36) and (2.90±0.46) respectively. Future time perspective was positively correlated with professional self-concept and career decision-making self-efficacy, and there was positive correlation between the latter two variables (all P<0.05). Future time perspective had a significant positive prediction effect on career decision-making self-efficacy (P<0.05), and it was still significant after adding a mediator of professional self-concept (P<0.05), and the intermediary effect accounted for 34.80% of the total effects. Conclusion The career decision-making self-efficacy among master of nursing students is at a medium and above level, and their professional self-concept plays a part mediating role in the relationship between future time perspective and career decision-making self-efficacy. Nursing educators should pay attention to the cultivation and development of future time perspective and professional self-concept of master of nursing students, so as to improve their confidence in career selection and make effective career decisions.