Objective To study hyperbaric oxygen on left ventricular ejection fraction preserved by the influence of left ventricular remodeling in patients with heart failure. Methods A total of 110 patients with heart failure and normal ejection fraction were randomly allocated into the control group (n=55) and the HBO group (n=55). The control group were given the routine therapy, the HBO group were treated with hyperbaric oxygen on the basis of conventional drug. The application of color doppler ultrasound before and after treatment for 3 months left ventricular structure indicators. Results Left ventricular structure indicators were significantly decreased (LVDd、IVSD、LVPWD、LVMI)(P<0.01). Compared with the control group the difference was statistically significant (P<0.05). Follow-up of 3 months, The treatment group composite cardiovascular events was fewer than the control group and had significant difference (P<0.05). Conclusion Hyperbaric oxygen therapy can significantly improve left ventricular ejection fraction preserved by heart failure of left ventricular diastolic and systolic function and reverse left ventricular remodeling,And can reduce the happening of cardiovascular events.