1, chest x-ray: it shows that the lower part of the sternum and the adjacent rib cartilage are obviously sunken, and the spine and sternum spacing is shortened. In severe cases, the end of the sternum meets the vertebral body of the spine. The heart is left shifted and the lung texture is thickened. Very few children often have chronic inflammation of the lungs and pulmonary atelectasis. 2.CT scan: CT scan can more accurately evaluate the degree of depression, symmetry, heart compression and displacement, lung compression and other combined problems of funnel chest. CT scan can help to judge more objectively when performing surgical procedures. 3.Electrocardiogram: Sinus arrhythmia, bidirectional or inverted P waves, incomplete right bundle branch block, cardiac stress transposition, and electric axis deviation are most commonly seen. 4.Cardiac and pulmonary function tests: In severe cases, the cardiopulmonary function decreases. 5.Blood biochemistry: some patients have mild anemia and increased serum alkaline phosphatase.