Objective: Burnout is common in mental health nurses because of work-related stress. Burnout has a negative impact on nurses' health and work performance. The prevalence of high burnout in mental health nurses has been inconclusive across studies. This meta-analysis aimed to estimate the pooled prevalence of high burnout in mental health nurses in China. Methods: Electronic databases (PubMed, EMBASE, PsycINFO, Web of Science, CNKI, WanFang and SinoMed) were independently and systematically searched from their commencement date up to 14 May 2018. Studies that reported the prevalence of any of the 3 burnout dimensions (high Emotional Exhaustion (EE), Depersonalization (DP), and low Personal Accomplishment (PA)) as measured by the Maslach Burnout Inventory (MBI) were included and analyzed using the random-effects model. Results: A total of 19 studies were included in this meta-analysis. The pooled prevalence of high EE was 28.1% (95% CI: 20.4–35.8%), DP was 25.4% (18.1–32.6%) and low PA was 39.7% (28.3–51.1%). Subgroup analyses found that short working experience, use of MBI-Human Services Survey (HSS), and younger age had moderating effects on prevalence of high burnout. Conclusions: Burnout is common in mental health nurses in China. Considering its negative impact on health and work performance, regular screening, preventive measures and effective interventions should be implemented.