Renin-angiotensin system inhibitors (RASI) [including angiotensin-converting enzyme inhibitor (ACEIs), angiotensin II receptor blocker (ARBs), renin inhibitors] are important therapeutic drugs for cardiovascular and renal vascular diseases. From the pharmacological mechanism analysis, the combination of the above drugs (the strategy of dual RAS blockade) may have synergistic effect on the treatment of cardiovascular and renal vascular diseases, and reduce their respective adverse reactions. However, some previous clinical studies showed that the dual RAS blockade did not significantly benefit patients with cardiovascular and renal vascular diseases, but increased the risk of hyperkalemia, hypotension and renal function damage. Therefore, the European and American drug regulatory agencies have warned that clinical use should be cautious, but this warning remains positive for individualized drug use, especially emphasizing that the combination of ACEI and ARB drugs in patients with heart failure may be effective, and the premise of the combination is to closely monitor the renal function, electrolyte and blood pressure of patients. Based on the above reasons, the current clinical guidelines for cardiovascular diseases often do not recommend the combination of ACEIs and ARBs. However, there were also evidence that low-dose ACEIs combined with ARBs can achieve more effective RAS blocking, and the adverse effects are rare, especially in patients with chronic kidney disease with proteinuria.