Abstract: Transformational leadership is one of the important factors that affect safety performance. In order to clarify the mechanism of transformational leadership, organizational identity and affective commitment on safety performance, a hypothesis model of four-factor relationship was established on the basis of literature research and questionnaire survey. The structural equation model(SEM) and Bootstrap were used to analyze 326 individual valid sample data from five coal mines. The results show that transformational leadership, organizational identity, affective commitment and safety performance are significantly positively correlated to each other. Transformational leadership can not only directly have a significant positive impact on safety performance, but also indirectly influence safety performance through two pathways, namely affective commitment, as well as the chain mediation of organizational identification and affective commitment. It means that transformational leadership can improve safety performance by enhancing the organizational identity of miners and enhancing their affective commitment to the organization.