The development of mental health among students has become a crucial objective and focus in numerous countries, with teachers serving as the primary guardians of their mental well-being. As such, enhancing teachers’ mental health literacy has emerged as a key strategy and priority in this endeavor. The purpose of this study is to conduct a comprehensive analysis of the experimental effects associated with improving teachers’ mental health literacy. The study seeks to provide substantiated evidence and innovative strategies for enhancing teachers’ mental health literacy. A systematic search was conducted using five English databases (PubMed, Web of Science, EBSCO, Springer Link, ProQuest) and three Chinese databases (WanFang, CNKI, and VIP) to identify controlled trials evaluating the immediate effect and tracking effect of the intervention experiment on enhancing teachers’ mental health knowledge, anti-stigma, willingness, or behavior to seek help. Relevant peer-reviewed articles (n = 20) were selected for further analysis through the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA-P), with a total of 7446 subjects. The findings revealed that the immediate effect of the intervention on teachers’ mental health literacy, knowledge, stigma, and assistance-seeking had significant moderate to substantial effects. The tracking effect value for knowledge was only moderately significant, and the others were not significant. The analysis of subgroup moderating variables revealed that differences in national economic development level and cultural type did not have a significant impact on the intervention of teachers’ mental health literacy. The results of this review revealed that intervention experiments can effectively improve teachers’ mental health literacy. Hence, it is prudent to pay more attention to the intervention of teachers’ mental health literacy and strengthen the scientific design of experiments to improve the effectiveness of the intervention.