In recent years, transesophageal echocardiography has a trend toward miniaturization, so it has great clinical significance and broad clinical application prospect in the management of Cardiac Surgery ICU patient. This paper presents the characteristics of miniaturized transesophageal echocardiography and its clinical application. And we also focused on the contrast between miniaturized transesophageal echocardiography and standard transesophageal echocardiography and transthoracic echocardiography.