Although the construct of well-being has been widely discussed among philosophers and writers since long time ago, scholars did not start to conduct related empirical studies until 1960s. In recent years, with the development of both Positive Psychology and Positive Organizational Behavior, the construct of employee well-being has caught increasingly more attention from organizational scholars. In this line of research, organizational justice has been regarded as a key factor which influences employee well-being. However, as for the specific impact of one particular type of justice, it has been largely ignored in extant studies. Our research thus focuses on the construct of interactional justice and aims to explore how and when interactional justice influences employee well-being. Specifically, we propose that interactional justice encourages employee well-being in the workplace. Moreover, drawing upon self-determination theory, we posit that psychological empowerment is the underlying mechanism that explains the positive effect of interactional justice on employee well-being. Furthermore, considering the role of individual difference, we argue that employees’ power distance weakens the relationship between interactional justice and psychological empowerment as well as the whole mediating mechanism. We collected our three-wave data from a large manufacturing company in Northern China. At time 1, we invited all 489 frontline employees to rate interactional justice. Two months later, at time 2, we invited all 376 employees who had returned time-1 survey to rate their own power distance as well as psychological empowerment. Another two months later, at time 3, we invited all 294 employees who had returned both time-1 and time-2 surveys to rate their own well-being. Meanwhile, employees’ demographic information including gender, age, education, and tenure with their supervisors were all obtained from the HR department. The final valid sample consisted of 199 employees (for a final response rate of 40.70%). Regression analysis, RMediation procedure, and bootstrapping technique were used to test the mediation, moderation, and moderated-mediation relationships among the study variables. Consistent with our predictions, the results indicated that interactional justice was positively related to employee well-being. And this relationship was mediated by psychological empowerment. Moreover, power distance negatively moderated the relationship between interactional justice and psychological empowerment, and also buffered the whole mediating mechanism. Overall, our research has extended the extant literatures from three primary perspectives. Firstly, this study has deepened our understanding of the relationship between organizational justice and employee well-being by paying specific attention to interactional justice and examining its link with employee well-being. Secondly, drawing upon self-determination theory, this study has explained how interactional justice impacts employee well-being through psychological empowerment. Thirdly, this study has further painted a more complete picture by exploring the contingent effect of power distance.