The COVID-19 pandemic has presented significant psychological challenges for healthcare workers in healthcare facilities. In particular, medical workers have to perform various tasks such as long-term contact with infected patients and epidemic prevention work, which can impact their psychological well-being making it difficult for them to maintain a high level of well-being. According to such a background, it is worth ex-ploring which factors have negative impacts on the level of psychological well-being, and it is important to re-veal the process behind this reduced psychological well-being. Therefore, this study focused on the main ele-ments affecting medical workers’ psychological well-being, such as relationship conflict, and aimed to identify the causal relationship between relationship conflict and psychological well-being. Furthermore, this study iden-tified and demonstrated the mediating role of job stress in the relationship between relationship conflict and psychological well-being. Additionally, the moderating effect of task conflict was examined on relationship conflict and psychological well-being, and the moderated mediation effect of task conflict was also examined. We surveyed 259 medical workers from Chinese medical institutions. The results showed that relationship conflict had a positive effect on work stress among healthcare workers. However, relationship conflict did not have a significant effect on the psychological well-being of healthcare workers. Work stress had a neg-ative effect on the psychological well-being of healthcare workers. The task conflict did not significantly moderate the effect of relationship conflict on psychological well-being, and the moderated mediation effect of task conflict was not significant. Overall, this study focused on exploring and verifying variables that lower the level of psychological well-being among healthcare workers and proposed methods to improve their psychological well-being. Specifically, this study differs from previous research by not focusing on methods to improve psychological well-being in the context of Chinese healthcare institutions, but rather exploring negative variables that lower psychological well-being and verifying the process behind the reduced psychological well-being. Finally, by revealing the process behind the reduced psychological well-being, our research makes a valuable con-tribution to the field of psychological well-being.