As professional helpers, nurses are in a high-risk and high-pressure working environment and often experience traumatic events or scenes, such as patient death; therefore, they are more probably to suffer trauma and lead to job burnout. Burnout is a psychological syndrome that is characterized by emotional exhaustion, depersonalisation and low personal accomplishment. It has been proven to be closely linked to the intention to leave (Dall'Ora et al., 2020).A meta-analysis showed that the overall prevalence of burnout symptoms among global nurses was 11.23% before COVID-19 (Woo et al., 2020). Furthermore, the COVID-19 pandemic has had an even larger impact on nurses' mental health. According to the study by Galanis (Galanis et al., 2021), during the COVID-19 outbreak, 34.1%, 15.2% and 12.6% of nurses experienced high levels of emotional exhaustion, low personal accomplishment and depersonalisation, respectively. Therefore, measures should be urgently taken to reduce nurses' job burnout and hinder wastage of the labour force.Based on the broaden-and-build theory of positive emotions, positive emotions such as joy, interest, contentment and love can broaden an individual's momentary thought-action repertoire and build more lasting personal resources to help people generate more