Objective To explore the application and follow-up monitoring and diagnostic value of lung ultrasound (LUS) in elderly patients(≥75y) with novel coronavirus pneumonia (COVID-19). Methods Data of 25 COVID-19 elderly patients admitted to the Department of Internal Medicine from November 1, 2022 to January 15, 2023 were retrospectively analyzed and summarized. In addition to clinical data, dynamic monitoring of LUS was performed, and the results were compared with lung CT results. The examination results, as well as the prediction and impact on the course of disease were observed. Results LUS imaging indicated that patients had different degrees of interstitial lung injury, including discrete type B line (interstitial exudation) or fusion type B line (alveolar infiltration) and lung consolidation (alveolar collapse). With the improvement of the disease, the range of lung consolidation seen in LUS was reduced, the B-line was gradually sparse to dissipate, and the A-line appeared. Conclusions The results of LUS and chest CT in the same period are consistent. LUS examination is safe, simple, reproducible, and can be monitored dynamically in real time. It can be used as a primary screening method, and also be used in special patients to assist clinical treatment decision-making.