Objective To conduct a network Meta-analysis quantifying the effects of different kinds of exercise on middle-aged and elderly people with or at a high risk of cardiovascular disease (CVD), and to provide evidence-based suggestions on cardiac function improvement and CVD prevention and treatment. Methods We searched Pubmed, the Cochrane Library, Embase, Web of Science,CNKI, Sinomed, VIP, Wanfang Med, and Wanfang Data to retrieve RCTs on effect of exercise on cardiac function of middle-aged and elderly people. Data were analyzed using RevMan5.4 and Stata16.0. Results We included 48 RCTs that involved 3 073 participants. In terms of HR reduction, the exercises were ranked as follows:interval aerobic exercise (SUCRA=73.30), continuous aerobic exercise (SUCRA=72.00), high-intensity interval training (SUCRA=67.50), continuous aerobic exercise combined with resistance training (SUCRA=62.80), and resistance training (SUCRA=20.10). In terms of LVEF increase, the effects of interval aerobic exercise were better than continuous aerobic exercise combined with resistance training (MD=2.88,95%CI:0.01-5.76); compared with continuous aerobic exercise, interval aerobic exercise (MD=4.02,95%CI:1.72-6.31), and resistance training (MD=2.32,95%CI:0.17-4.48) were better; different kinds of exercise were ranked as follows:interval aerobic exercise (SUCRA=95.10), resistance training (SUCRA=72.40), continuous aerobic exercise combined with resistance training (SUCRA=51.70), high-intensity interval training (SUCRA=50.80), continuous aerobic exercise (SUCRA=29.50). In terms of heart rate variability (HRVS), exercise had a good effect on SDNN increase (MD=9.05,95%CI:3.10-15.00,P<0.05) and little effect on LF/HF radio (MD=-0.18,95%CI:-0.56-0.20,P>0.05). Conclusion Exercise can improve cardiac function of middle-aged and elderly people by decreasing HR, raising LVEF, and improving HRV. Interval aerobic exercise, continuous aerobic exercise, high-intensity interval training, resistance training, and continuous aerobic exercise combined with resistance training all can improve cardiac function of this population to a certain extent. Among them, interval aerobic exercise has a more comprehensive effect on improvement of cardiac function and is the more effective intervention in reducing HR and increasing LVEF.