Objective To investigate the correlations between the essential frailty toolset (EFT) score and five times sit-to-stand (FTSTS), 30-second sit-to-stand (30s-STS), 1-minute sit-to-stand (1min-STS), and 6-minute walk test (6MWT) in patients with coronary artery disease (CAD) aged 60-80 years old, so as to determine the physical exercise function indicators for clinical assessment of patients with CAD combined frailty. Methods A total of 78 CAD patients admitted to the Department of Cardiovasology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from Jan. 2020 to Dec. 2021 were retrospectively enrolled. They were assigned to 2 groups according to the EFT score: frailty group (EFT score≥1, n＝28) or non-frailty group (EFT score＝0, n＝50). The basic information, FTSTS, 30s-STS, 1min-STS, 6MWT, left ventricular ejection fraction (LVEF), and blood indexes were collected, and their correlations with frailty were statistically analyzed. Receiver operating characteristic (ROC) curve was used to analyze the diagnostic value of the above indexes for frailty in patients with old myocardial infarction (MI) or without MI, and the optimal cutoff value was determined. Results Compared with the non-frailty group, the frailty group had lower body mass index (［23.14±3.03］ kg/m² vs ［24.78±3.29］ kg/m², P＝0.033), higher N-terminal pro-brain natriuretic peptide level (199.40 ［55.32, 1 012.65］ mmol/L vs 99.75 ［41.36, 217.75］ mmol/L, P＝0.016), and lower LVEF, 30s-STS, 1min-STS and 6MWT (［56.99±10.20］% vs ［62.15±6.45］%, ［10.93±2.98］ repetitions vs ［14.50±2.63］ repetitions, ［21.32±5.45］ repetitions vs ［27.30±5.62］ repetitions, and ［412.84±62.34］ m vs ［470.04±56.41］ m, all P＜0.01). Spearman correlation analysis showed that the 30s-STS, 1min-STS, and 6MWT were moderately or highly negatively correlated with the EFT score (r_s＝－0.575, －0.493, and －0.467). ROC curve analysis showed that in the patients without MI the area under curve (AUC) value was 0.85 for 30s-STS diagnosing frailty (sensitivity 66.7%, specificity 92.9%, optimal cutoff value ≤13 repetitions), 0.82 for 1min-STS (sensitivity 60.6%, specificity 92.9%, optimal cutoff value ≤27 repetitions), and 0.80 for 6MWT (sensitivity 78.8%, specificity 78.6%, optimal cutoff value ≤446.55 m); in the patients with old MI the AUC value was 0.81 for 30s-STS (sensitivity 94.1%, specificity 71.4%, optimal cutoff value ≤10 repetitions), 0.72 for 1min-STS (sensitivity 94.1%, specificity 57.1%, optimal cutoff value ≤19 repetitions), and 0.68 for 6MWT (sensitivity 94.1%, specificity 42.9%, optimal cutoff value ≤387.45 m). Conclusion The 30s-STS, 1min-STS, and 6MWT are moderately or highly negatively correlated with the degree of frailty in CAD patients, and they are effective tools for clinical assessment of frailty. The 30s-STS is a good physical exercise function indicator for clinical assessment of frailty in CAD patients with or without MI combined frailty.