Posterior cranial fossa decompression surgery is generally used for large cerebellar infarcts and corresponding tumor growths, and the surgical approach is to incise the skin in the midline at the back of the neck and separate the corresponding muscles and tissues. Care must be taken to stop the hemorrhage, as there is a venous plexus here that can easily hemorrhage if it is subjected to rupture, so attention must be paid to this aspect. Separate the corresponding muscles and ligamentous tissues to the two sides, expose the posterior occipital bone, apply the cranial drill to drill holes, maintain a relatively stable area, and use the milling cutter to mill down a circle of cranial bone, and the basic surgery will be done. However, if you want to further explore the brain tissue or remove the tumor, you need to open the dura for suspension, go in and directly remove the necrotic brain tissue as well as the inactivated brain tissue, you can also do the internal decompression, and the surgery is basically finished, layered suture, placement of bone flap, and even in some cases, you can also go to the bone flap for decompression, and you can sew up the scalp at a later stage, and the surgery is finished.