Objective To evaluate the effect of phase I exercise rehabilitation on cardiac rehabilitation in patients with acute decompensated heart failure（ADHF）. Methods Two researchers independently searched and screened PubMed， Web of Science， Embase， Cochrane Library， CINAHL， CNKI， VIP， Wanfang Database and SinoMed for the randomized controlled study on the effect of phase I exercise rehabilitation on cardiac rehabilitation of patients with acute decompensated heart failure until October 2023. RevMan5.3 software was used for data extraction and analysis. Results A total of 8 RCTs involving 681 patients were included. Meta-analysis results showed that phase I exercise rehabilitation could improve the 6-minute walk distance[MD=56.80， 95%CI（20.82， 92.78）， P<0.01] and physical function [MD=1.25， 95%CI（0.61， 1.89）， P<0.01]， reduce all-cause readmission[OR=0.49， 95%CI（0.26， 0.91）， P=0.03]， improve quality of life[MD=-15.74， 95%CI（-20.03， -11.44）， P<0.01] of ADHF patients compared with routine care. However， there was no difference in NT-proBNP[MD=-74.36， 95%CI（-248.60， 99.87）， P=0.40] and 3-month rehospitalization[OR=0.48， 95%CI（0.16， 1.50）， P=0.21]. No adverse events occurred in the two groups during the intervention period. Conclusion Phase I exercise rehabilitation is helpful to improve the exercise tolerance and quality of life of patients with ADHF， and it is effective and safe to improve the 6-minute walk distance and short physical performance score. However， there was only an improvement trend in NT-proBNP level and 3-month rehospitalization rate， and there was no statistical power. Large sample and high-quality studies are still needed to evaluate its individual response and long-term effects.