Due to the potential influence of motivation on employee safety behaviors and safety outcomes, exploring the antecedents that affect employees’ motivational states is critical in the workplace safety. Considering the significant role of leaders and their interpersonal emotion-related characteristics, our research introduces the construct of leader trait affective presence and investigates its effects on employee safety behaviors via work engagement. In a multisource study based on 467 dyads of leaders and their employees in a nuclear power plant, we tested and supported hypotheses that leader positive affective presence was positively related to employee work engagement, whereas leader negative affective presence was negatively related to employee work engagement. And work engagement was positively related to safety behaviors. Furthermore, leader affective presence has an indirect effect on employee safety outcomes via work engagement. These findings indicate the theoretical value of leader trait affective presence in shaping employee motivational state and further safety behaviors, as well as practical implications for safety organizations.