Objective To investigate clinical value for the risk model of acute heart failure index (AHFI) combined with emergency heart failure mortality risk grade (EHMRG) in evaluating clinical outcomes and prognosis of patients with acute heart failure (AHF). Methods The present prospective observational cohort study enrolled a total of 228 patients with AHF who were admitted to our hospital from January 2019 to January 2020. The AHF patients were divided into four groups: (1) the high AHFI and high EHMRG group, n = 61; (2) the low AHFI and low EHMRG group, n = 92; (3) the high AHFI and low EHMRG group, n = 34; (4) the low AHFI and high EHMRG group, n = 41. AHFI and EHMRG were used to identify the risk of death for AHF patients. Serum levels of Troponin I, B-type natriuretic peptide (BNP), and NT-pro-B-type natriuretic peptide (NT-proBNP) were detected by the ELISA method. Kaplan-Meier curve was performed for analysis of survival time and a logistic regression model was used to analyse 1-year mortality of patients. Pearson’s analysis was used to determine the correlation between biomarkers and EHMRG. Results AHFI combined with the EHMRG model was associated with cardiac function status and EHMRG score was positively related to the level of Troponin I, BNP, and NT-proBNP. AHF high-risk AHFI and high-risk EHMRG indicated that patients might have a higher incidence of MACEs during hospitalisation. In addition, AHFI and high-risk EHMRG groups had shorter survival times, and AHFI was associated with 1-year mortality and was the risk factor for 1-year mortality. Conclusion AHFI combined with a high EHMRG risk model was associated with clinical outcomes and prognosis.