To improve safety performance and explore the dark side of transformational leadership (TFL), this study tested the cross-level impact of differentiated transformational leadership (DTFL) on employee safety performance, especially the mediating role of team efficacy and self-efficacy. Total 917 front-line employees from 107 teams in 3 branches of an oil field completed questionnaire survey. The results showed that DTFL was negatively correlated with safety performance and team and self-efficacy, team and self-efficacy positively affected safety performance, and the latter played the mediating roles in the relationship between DTFL and safety performance.