Cardiac rehabilitation therapy is beneficial to patients with coronary heart disease(CHD). This study evaluated the impact of cardiac rehabilitation on young patients(≤45 years old) undergoing percutaneous coronary intervention(PCI). Methods This prospective cohort study enrolled 100 patients with CHD, aged ≤45 years old, undergoing PCI at a tertiary hospital from March 2019 to December 2020. They were randomly assigned to the conventional group and the cardiac rehabilitation(CR) group, both treated for 6 months. Research indicators included blood lipid level, anaerobic threshold(AT), peak kilogram oxygen uptake(Peak VO2/kg), peak ventilation volume(VEpeak), stroke volume(SV), peak oxygen pulse(Peak O2pluse), peak metabolic equivalent(METpeak), left ventricular ejection fraction(LVEF), left ventricular diastolic internal diameter(LVEDd), Borg fatigue Scale score, Anxiety Self-Assessment Scale(SAS) and Depression Self-Evaluation Scale(SDS) scores.Results At the 6thmonth of the treatment, the levels of blood lipid triglyceride(TG), total cholesterol(TC), low density lipoprotein cholesterol(LDL-C), Borg fatigue scale score, SAS score and SDS score were significantly reduced(P<0.05) in both groups, especially in CR group. Meanwhile, compared with pre-treatment, LVEF, AT,Peak VO2/kg, VEpeak, SV and METpeak increased significantly(P<0.05) in CR group, LVEDd decreased significantly(P<0.05) in CR group at 6 thmonth of treatment. There was no significant difference about the relevant data above in the conventional group. In addition, LVEF, AT, Peak VO2/kg, VEpeak, SV, METpeak and Peak O2pluse level were significantly elevated(P<0.05) and LVEDd decreased significantly(P<0.05) in CR group compared with the conventional group. Conclusions Cardiac rehabilitation treatment can not only significantly reduce the blood lipid level, relieve anxiety and depression of young PCI patients with coronary heart disease, but also significantly improve the reconstruction of ventricular structure, exercise tolerance and cardiac function. [S Chin J Cardiol 2021;22(3):182-190]