According to statistics, in some cases, surgery for pituitary tumor is not suitable: 1, the large anterior spongy sinus extends forward to the anterior pituitary and the anterior edge of the saddle diaphragm, and even covers the entire anterior wall of the pterygoid saddle, which is prone to haemorrhage when the saddle base dura is incised during surgery; 2, the saddle diaphragm is too thin and the saddle diaphragm hole is too large. The internal carotid artery is free in the pterygoid sinus or in the anterolateral part of the pterygoid sinus, and the surface of its bulge is not covered by bone and is exposed in the pterygoid sinus. It is easy to be damaged during the operation.