Aortic stenosis accounts for a large proportion of valvular heart disease in China. This article described an unusual case of severe aortic stenosis with severe cardiopulmonary decompensation treated by emergency transcatheter aortic valve replacement. Preoperative assessment was performed by transesophageal echocardiography. The extracorporeal membrane oxygenation team was informed to be ready. During the operation, no obvious perivalve leakage was observed after valve released. The transvalvular pressure gradient decreased to 7 mm Hg (1 mm Hg=0.133 kPa).The patient’s symptoms were completely relieved after the operation, and no adverse events occurred during the hospitalization. After discharge, color Doppler echocardiography showed that stenosis was eliminated, cardiac function was improved, no significant perivalvular leakage was observed, and pulmonary hypertension reduced to moderate. The success of this operation confirmed the efficacy of emergency transcatheter aortic valve replacement, and showed that after a rigorous evaluation, emergency transcatheter aortic valve replacement may be a reasonable choice for patients with severe aortic valve stenosis.