OBJECTIVE To systematically evaluate the clinical efficacy of dapagliflozin in the treatment of heart failure with diabetes mellitus type 2. METHODS The clinical trials of dapagliflozin in the treatment of heart failure with diabetes mellitus type 2 were searched in Embase, PubMed, Web of Science, Cochrane Library, VIP, CNKI and Wanfang databases from the establishment of the database to March 18, 2022. The RevMan 5.3 software was used for meta-analysis, and the TSA 0.9 software was used for sequential analysis. RESULTS The 31 RCT studies meeting the criteria were finally included, involving 2 906 patients. Meta-analysis showed that compared with the control group, the experimental group significantly improved LVEF[MD=4.43, 95% CI(3.35, 5.50), P<0.000 01], total effective rate[MD=4.19, 95%CI(2.52, 6.99), P<0.000 01], and reduced NT-proBNP[MD=–451.84, 95%CI(–608.09, –295.60), P<0.000 01], LVEDD[MD=–2.74, 95%CI(–3.67, –1.82), P<0.000 01, Hb1ac[MD=–0.88, 95%CI(–1.19, –0.57), P<0.000 01], FPG[MD=–1.10, 95%CI(–1.45, –0.75), P<0.000 01], 2hPG[MD=–2.52, 95%CI(–3.37, –1.66), P<0.000 01] and the incidence of adverse reactions[MD=0.63, 95%CI(0.47, 0.83), P=0.001]. Sequential analysis showed that the effect of dapagliflozin on LVEF in patients with heart failure with type 2 diabetes was accurate, and the possibility of excluding false positive was possible. CONCLUSION The treatment of heart failure with diabetes mellitus type 2 with good efficacy and safety is achieved by dapagliflozin, but it still needs to be included in more high-quality RCT studies for further demonstration.