Transesophageal cardiac ultrasound, in which an ultrasound probe is placed into the esophagus and the internal structures of the heart are probed from behind and forward, can be divided into two-dimensional transesophageal ultrasound and three-dimensional transesophageal ultrasound, the latter with clearer images and clearer diagnosis, which can avoid the effects of obesity, emphysema and thoracic deformities compared with ordinary transthoracic ultrasound. This examination modality can display clear images, improve the sensitivity and reliability of cardiovascular disease diagnosis, and facilitate ultrasound monitoring and evaluation of cardiac surgery.