Objective: To analyze the effect of sacubitril valsartan sodium combined with metoprolol on cardiac function and peak oxygen consumption (VO2 peak) in patients with heart failure (HF). Methods: A total of 64 patients with HF treated at the Second Hospital of Xingguo from January to December 2024 were selected, and randomly assigned to two groups. The standard group (n=32) received conventional treatment and treatment with sacubitril valsartan sodium tablets. On this basis, the Betaloc group (n=32) was additionally treated with metoprolol tartrate tablets. The clinical efficacy, cardiac function [left ventricular ejection fraction (LVEF), left ventricular fractional shortening (LVFS), left ventricular end diastolic diameter (LVEDD), 6-minute walking distance (6MWD)], cardiopulmonary function [peak heart rate, VO2 peak, the slope relating minute ventilation to carbon dioxide output (VE/VCO2 slope), maximum metabolic equivalents (METsmax)], and adverse reactions after 3 months of continuous treatment were compared between the groups. Results: The total response rate and the incidence of adverse reactions were comparable between the two groups (P>0.05). After treatment, LVEF, LVFS, 6MWD, VO2 peak and METsmax in the Betaloc group were greater than those in the standard group (P<0.05). LVEDD, peak heart rate and VE/VCO2 slope were smaller than those in the standard group (P<0.05). Conclusion: The combined treatment with sacubitril valsartan sodium and metoprolol can improve cardiac function and increase VO2 peak in patients with HF, with significant therapeutic effects.