Transforming employees' man-nature orientation into their green behavior is a key micro foundation for achieving sustainable development in enterprises, but the mechanism behind it is not yet clear. Based on the cognitive-affective system theoryof personality, this study investigated the cognitive (i.e., employees' connectedness to nature)-affective (i.e., employees' harmonious environmental passion) mediating roles and the moderating role of environmentally specific servant leadership between employees' man-nature orientation (i.e., an element of employees' personality system) and their green behavior. Empirical results of 367 employees from enterprises in 25 provinces by a three-wave follow-up survey verified that the cognitive mediation path of the impact of employees' man-nature orientation on their green behavior, and confirmed that environmentally specific servant leadership positively moderates employees' cognitive (i.e., connectedness to nature) and emotional (i.e., harmonious environmental passion) dual mediating effects mentioned above. These conclusions provide theoretical and practical foundation for solving the problem of how to put the idea of harmonious coexistence between human and nature into practice at the employee level.