Background This study was designed to evaluate the efficiency and safety of combination therapy with sodium-glucose cotransporter 2 (SGLT2) inhibitors and renin-angiotensin system blockers such as angiotensin-converting enzyme inhibitor (ACEI) and angiotensin receptor blocker (ARB) in patients with type 2 diabetes mellitus (T2DM). Methods We searched the PubMed, Embase, Web of Science and Cochrane Library databases from their inception to May 2020. Two authors independently performed study selection, risk-of-bias assessment and data extraction. The quality and risk of bias were assessed by the Cochrane Risk of Bias Tool. Statistical heterogeneity was determined by the I-2 statistics. Results Seven studies including 1757 patients were analysed. Compared with ACEI/ARB alone, combination therapy with SGLT2 inhibitors and ACEIs/ARBs produced a reduction in systolic blood pressure (SBP) [weighted mean difference (WMD) -3.84 mmHg], diastolic blood pressure (DBP; WMD -1.06 mmHg), 24 h ambulatory SBP (WMD -4.59 mmHg), 24-h ambulatory DBP (WMD -2.08 mmHg), urine albumin:creatinine ratio (WMD -29.70%), evaluated glomerular filtration rate (WMD -3.46 mL/min/1.73 m(2)), haemoglobin A1c [standardized mean difference (SMD) -0.48], fasting plasma glucose (SMD -0.28), uric acid (SMD -0.35) and body weight (SMD -0.29). The risk of hypoglycaemia with combination therapy was higher than in the control group (risk ratio 1.37). As for the risks of total adverse events, genital infection and urinary tract infection, no significant difference was revealed. Conclusion Compared with ACEI/ARB alone, the combination therapy with SGLT2 inhibitors and ACEIs/ARBs in T2DM was effective and well-tolerated and could achieve additional effects including better control of blood pressure, improvement of renal outcomes, alleviation of long-term renal function and a decrease in blood glucose and body weight. The combination therapy showed an increased risk of hypoglycaemia.