ObjectivesTo summarise the effects of various types of aerobic exercise on the global cognitive function of the elderly with mild cognitive impairment (MCI).DesignA meta-analysis of randomised controlled trials (RCTs).Data sourcesPubMed, EMBASE and the Cochrane Library were searched for clinical RCTs from the earliest available records to March 2022.Eligibility criteria for selecting studiesWe included RCTs of subjects older than 60 years with MCI. The outcome indicators of cognitive function of interest were the Mini-Mental State Examination (MMSE) and the Montreal Cognitive Assessment (MoCA).Data extraction and synthesisTwo researchers independently screened the literature, extracted data and evaluated the quality of the included studies, with disagreements resolved by a third researcher. TheCochrane Handbook for Systematic Reviews of Interventionswas used to assess the risk of bias. Meta-analysis was performed by Review Manager V.5.3 software. Random-effect models were used for meta-analysis.ResultsA total of 1680 patients who participated in 20 RCTs were included in this study. Based on outcomes of MMSE analysis, the aerobic exercise, which was beneficial for global cognitive function in MCI patients, included multicomponent aerobic exercise (MD=1.79, 95% CI (1.41 to 2.17), p<0.01) and mind–body exercise (MD=1.28, 95% CI (0.83 to 1.74), p<0.01). The results of the meta-analysis of conventional aerobic exercise (MD=0.51, 95% CI (0.09 to 0.93), p=0.02) turned out to be statistically insignificant after sensitivity analysis (MD=0.14, 95% CI (-0.47 to 0.75), p=0.65). With the evaluation of MoCA, multicomponent aerobic exercise (MD=5.74, 95% CI (5.02 to 6.46), p<0.01), mind–body exercise (MD=1.29, 95% CI (0.67 to 1.90), p<0.01) and conventional aerobic exercise (MD=2.06, 95% CI (1.46 to 2.65), p<0.01) were showed significant beneficial effects for the patient. However, there was a high degree of heterogeneity between the results of multicomponent aerobic exercise (MMSE) and conventional aerobic exercise (MoCA), which was analysed and explored.ConclusionsIn general, multicomponent aerobic exercise and mind–body exercise were beneficial in improving global cognitive function in the elderly with MCI. Nevertheless, the improvement effect of mind–body exercise is more reliable compared with multicomponent aerobic exercise and conventional aerobic exercise.PROSPERO registration numberCRD42022327386.