OBJECTIVE: This paper aims to systematically evaluate the intervention effect of mind-body exercise on cancer-related fatigue in breast cancer patients. METHODS: Databases including PubMed, the Cochrane Library, Embase, Web of Science, CNKI, Wanfang Data, and SINOMED were retrieved to collect randomized controlled trials on the effects of mind-body exercise on relieving cancer-related fatigue in breast cancer patients. The retrieval period started from the founding date of each database to January 6, 2021. Cochrane bias risk assessment tools were used to evaluate the methodological quality assessment of the included literature, and RevMan 5.3 software was used for meta-analyses. RESULTS: 17 pieces of researches in 16 papers were included with a total of 1133 patients. Compared with the control group, mind-body exercise can improve cancer-related fatigue in breast cancer patients. The combined effect size SMD = 0.59, 95% CI was [0.27, 0.92], < 0.00001. Doing Tai Chi for over 40 minutes each time with an exercise cycle of ≤6 weeks can improve cancer-related fatigue in breast cancer patients more significantly. Sensitivity analysis shows that the combined effect results of the meta-analysis were relatively stable. CONCLUSION: Mind-body exercise can effectively improve cancer-related fatigue in breast cancer patients.