Squatting phenomenon refers to a special forced position, mainly due to congenital tetralogy of Fallot children, he will walk, or during the sitting time will appear to bend the legs with the special position of fraud section, and then will return to normal walking this situation will occur repeatedly. Tetralogy of Fallot is a common form of congenital heart disease, and it is a more serious and comprehensive heart malformation. The risk of tetralogy of Fallot is very high and it has a significant impact on the growth and development of the child. As a common clinical manifestation of complex congenital heart disease, what is the clinical diagnosis of squatting phenomenon? The following is the diagnosis of squatting phenomenon: according to the patient’s restricted activity, cyanosis is obvious after exercise and accompanied by shortness of breath, dyspnea, like squatting, growth and development is backward, and in serious cases, hypoxic syncope and convulsions can occur; physical signs can be seen conjunctival and nail cyanosis, pestle finger, grade II-IV rough jet-like systolic murmur can be heard at the left edge of the sternum on auscultation, the second pulmonary valve area sound disappears; supplemented by oxygen saturation, electrocardiogram and X-ray examination, right ventricular hypertrophy, aortic widening, bootstrap heart, cardiac catheterization, right heart catheterization, echocardiography and Doppler, etc. can clarify the diagnosis. The diagnosis of squatting phenomenon mainly relies on clinical manifestations and some auxiliary examinations to confirm the diagnosis. Every patient with squatting phenomenon should go to the hospital for examination in time, so as not to miss the time for treatment.