Workplace bullying is one of the focuses of organizational behavior research in recent years. Previous studies have shown that it is not only an important factor affecting employees' career performance, but also affects employees' life happiness, physical and mental health, and even their sleep quality. However, it is a pity that the mechanism of workplace bullying on sleep quality is still unclear in China's workplace environment. Therefore, in order to further explore the mediating mechanism and possible regulating mechanism of the impact of workplace bullying on employees' sleep quality, we conducted an online survey study on 436 employees. SPSS 24.0 and PROCESS were used to analyze the data results, and the Bootstrap method was used to analyze the mediation effect. The results found that: 1) workplace bullying was negatively related to sleep quality; 2) affective rumination mediated the relationship between workplace bullying and sleep quality and 3) this indirect effect was moderated by psychological detachment, specifically when workplace bullying is low, individuals with high psychological detachment are better able to cope with it than those with low psychological detachment. High psychological disengaged individuals always had lower levels of affective rumination than low psychological disengaged individuals. Research significance: The results of this study can help reduce the damage of workplace bullying to the sleep quality of employees, thus improving the happiness of life of employees, helping to improve the management ability of enterprises, and contributing to the development of a well-off society.