Based on the job demands resources（JD - R）model，we used convenience sampling to select 1032 on-duty nursing staff in a Grade - A tertiary hospital to conduct a questionnaire survey to explore the relationship between the mechanism of work hours， burnout， perceived level of mindfulness and work performance. The results found that the working hours of nursing staff increased，while the work performance decreased（β =- 0.10，P ＜0.05），and burnout mediated between working duration and work performance of nursing staff. The mindfulness awareness level moderated the mediation model（β=0.01，P＜0.01）. Nursing staff with high mindfulness perception levels increased their job performance with the increase in working hours（β= 0.10，P＜0.05）. We recommend improving mindfulness awareness，which can help to alleviate burnout and improve their work performance.