To systematically review the effects of Tai chi on sleep quality, depression, and anxiety in patients with insomnia. The electronic databases including PubMed, Cochrane Library, Web of Science, Embase, China National Knowledge Infrastructure (CNKI), WanFang Data, Chinese Biomedical Literature Database (CBM), and VIP Database for Chinese Technical Periodicals (VIP) were retrieved and screened by computer. Randomized controlled trials (RCT) on patients with insomnia who practiced Tai chi were collected, and the RCT risk of bias assessment criteria was used to evaluate the methodological quality of the included studies. The combined effect size was expressed as the weighted mean difference (WMD), with a confidence interval of 95% (CI). Review Manager 5.4 and Stata16.0 were used for heterogeneity analysis and sensitivity analysis. Tai chi reduced the patients' Pittsburgh sleep quality index (PSQI) score (WMD = -1.75, 95% CI: -1.88, -1.62, p < 0.001); Hamilton depression scale (HAMD) score (WMD = -5.08, 95% CI: -5.46, -4.69, p < 0.001), Hamilton anxiety scale (HAMA) score (WMD = -2.18, 95% CI: -2.98, -1.37, p < 0.001), and self-rating anxiety scale (SAS) score (WMD = -7.01, 95% CI: -7.72, -6.29, p < 0.001). Tai chi exercise has a good preventive and ameliorating effect on insomnia, which can relieve patients' depression and anxiety, simultaneously enhancing various functions of the body. However, most of the included studies reported random assignment with some lack of specific descriptions, and the blinding of participants was difficult to achieve due to the nature of exercise, which may cause bias. Therefore, more high-quality, multi-center, and bigger-sample studies need to be included in the future to further verify the results.