Objective To investigate the effect of low molecular weight heparin combined with Furosemide on cardiopulmonary function and blood gas analysis indexes in elderly patients with chronic pulmonary heart disease (CPHD). Methods A total of 60 elderly patients with CPHD admitted to Heshan People's Hospital from July 2020 to December 2021 were divided into the control group (30 cases, treated with the conventional treatments of vasodilator, antiasthmaticexpectorant, anti-infection, low-flow oxygen inhalation, correction of water and electrolyte imbalance) and the observation group (30 cases, treated with Low molecular weight heparin combined with Furosemide on the basis of conventional treatment), patients in both groups were given continuous treatment for 14 days. The clinical efficacy, disappearance time of clinical symptoms, cardiac function, pulmonary function, blood gas analysis indexes before and after treatment, and the occurrence of adverse reactions during treatment of patients in the two groups were compared. Results The total clinical effective rate of patients in the observation group and the control group were 96.67% and 70.00% respectively, and the observation group was significantly higher than the control group; compared with the control group, the disappearance time of the clinical symptoms edema, shortness of breath in the observation group shortened; stroke volume (SV), left ventricular ejection fraction (LVEF), the percentage of measured forced expiratory volume in one second in prediction (FEV1% pred), forced expiratory volume in one second/forced vital capacity (FEV1/FVC), arterial partial pressure of oxygen (PaO2) in both groups increased significantly compared with before treatment, and the observation group was significantly higher than the control group; the arterial blood carbon dioxide partial pressure (PaCO2) significantly decreased compared with before treatment, and the observation group was significantly lower than the control group (all P<0.05). Conclusion Elderly patients with CPHD treated with low molecular weight heparin combined with furosemide can effectively improve cardiopulmonary function, relieve symptoms such as edema and shortness of breath, regulate blood gas analysis indicators, and do not increase adverse reactions, which has good safety.