This study aims to explore how perceived teacher support influences university students' career decision-making self-efficacy. To this end, a moderating model with proactive personality as a moderating variable was proposed. Data from 753 university students in Chinese universities were analyzed. The results show that teacher support significantly and positively influenced university students' career decision-making self-efficacy, and proactive personality played a moderating role between teacher support and career decision-making self-efficacy. This study not only underscores the importance of teachers in the career development of university students but also highlights the crucial role of proactive personality in enhancing career decision-making self-efficacy. Importantly, this study contributes to the literature by examining these relationships within the context of China's collectivist culture, highlighting cultural nuances in teacher support and proactive personality effects. The findings provide new empirical support for career guidance and planning education in Chinese higher education, suggesting that educators should not only offer informational and emotional support but also focus on cultivating students' proactive personality traits to foster the comprehensive development of their career decision-making abilities.