Thoracoscopic mitral valve replacement is a common minimally invasive cardiac surgery procedure. However, small annulus, severe calcification of the annulus, and severe thickening of the posterior valve leaflet or sub valvular structure are the difficulties of thoracoscopic mitral valve replacement. Improper treatment can easily lead to left ventricular rupture or prosthesis-patient mismatch. This paper reports a thoracoscopic mitral bioprosthesis replacement case using the "chimney" technique in Guangdong Provincial People's Hospital and summarizes its operating key points. The patient was a 68-year-old female, weighing 36 kg. The preoperative diagnosis was rheumatic mitral stenosis and atrial fibrillation, the preoperative trans-thoracic echocardiogram showed the left ventricular end-diastolic diameter was 39 mm. The surgical effect was satisfactory. The patient was in good condition at the follow-up 2 months after the operation.