Patients with rheumatic heart disease who experience oliguria in the late stage should consider the possibility of heart failure as the cause. Due to heart failure leading to a decrease in cardiac output, renal blood perfusion is reduced, which in turn causes symptoms of oliguria. Additionally, if the patient also has renal function impairment, it will further exacerbate the symptoms of oliguria. It is important for patients with rheumatic heart disease who experience symptoms of oliguria to seek medical attention promptly and receive active treatment as soon as possible. Medications to control heart failure should be administered to increase the heart's contractility and cardiac output, improve renal perfusion, and diuretics should be given to increase urine output. With heart failure under control, the patient's condition can be alleviated. For patients with rheumatic heart disease, if there are indications for surgery, timely surgical treatment should be provided.