Background: Turnover intentions among nurses pose a significant challenge for healthcare systems globally. While numerous studies have explored the association between nurses’ well‐being and turnover intention, the underlying mechanisms remain insufficiently understood. Addressing the interactions among psychological capital, work engagement, well‐being and turnover intention is therefore essential. Aim: This study examined the chain‐mediating effects of psychological capital and work engagement on the relationship between well‐being and turnover intention. It aimed to identify the mechanisms influencing turnover intention tendencies among nursing staff and to propose strategies for stabilising nursing teams. Methods: A multistage random sampling approach was adopted across 21 hospitals in three provinces: Zhejiang (Eastern China), Heilongjiang (Central China) and Chongqing (Western China). Data were collected using the 5‐item World Health Organization Well‐Being Index, the Psychological Capital Questionnaire, the Utrecht Work Engagement Scale and the Turnover Intention Scale. Harman’s single‐factor test was employed to detect common method bias, and chain mediation analysis was conducted using the SPSS PROCESS macro. Results: Significant correlations were found between well‐being, psychological capital, work engagement and turnover intention ( p < 0.001). Well‐being directly influenced turnover intention (effect = −0.1227, 95% CI = −0.1421, −0.1033). Work engagement partially mediated the relationship between well‐being and turnover intention (effect = −0.0813, 95% CI = −0.0944, −0.0687). In addition, psychological capital and work engagement jointly mediated the relationship (effect = −0.0817, 95% CI = −0.0940, −0.0701). Conclusion: Nurses’ well‐being influences turnover intention via the serial mediation of psychological capital and work engagement. Hospital managers and governments should implement multifaceted interventions to mitigate turnover intentions and enhance the stability of nursing teams. Implications for Nursing Management: The findings highlight a potential pathway linking nurses’ well‐being to turnover intention. Nursing managers can adopt targeted interventions addressing this pathway to reduce turnover intention rates and ensure team stability.