Accidents can happen at any time in life, and damage to the skull after an impact can be very dangerous. It is important to have skull repair surgery in time to avoid further damage. Skull repair surgery has existed for a long time in human history, and the skull repair materials have undergone constant changes and become more and more advanced. Titanium mesh is one of the widely used materials in clinical practice, and it has certain advantages compared with the earlier materials. However, after some clinical proofs, titanium mesh leakage is one of the serious complications after skull repair, which has a great impact on patients’ body and mind, increases patients’ economic burden, and is easy to cause intracranial infection. So, why does the titanium mesh leak out? There are several common factors that lead to exposed titanium mesh in cranial bone repair: 1, titanium mesh is a metal foreign body, which may cause rejection and increase the chance of infection when implanted in the body. 2.The edge of trimmed titanium mesh is sharp and easy to cut the skin; the custom-made titanium mesh is too large and the overlap with skull is too wide, local bone laxity may cause the titanium nail to loosen; if the titanium mesh is poorly shaped, it may cause the edge to buckle and stab the skin. 3, the flap itself is too thin or too thin when cutting; the flap inner surface hemostasis when the electric knife or electrocoagulation is excessively cauterized; after large bone flap decompression surgery, the skull defect range is large, and the flap needed is also large, the more obvious the impact on blood supply, poor local skin nutrition, poor blood supply, the flap is prone to necrosis, rupture, incision cracking, repair material exposed. 4.The skin flap collapses obviously before cranial repair, the skin flap incision is sutured with high tension, the incision edge is severely damaged or improperly sutured resulting in skin inversion and difficult incision healing. 5.The wire knot buried in the incision in both surgeries is a foreign body, and if the reaction of the wire knot occurs, it will cause infection, local itching after infection, and the trauma will gradually expand after scratching. 6, poor intraoperative flap hemostasis or flap collapse is obvious, large subcutaneous dead cavity or subcutaneous fluid and blood accumulation after repair, separation of titanium mesh and dura mater, leaving a residual cavity, resulting in difficulty in healing of the incision. 7. Chronic cutting of the scalp by titanium mesh. The internal suction effect of intracranial low pressure on the scalp at the skull repair and the chronic cutting of the scalp by the fine titanium mesh frame make the three-dimensional titanium mesh gradually become shallow and finally lead to the exposure of the titanium mesh, which is a slow and progressive process. The exposed titanium mesh is very troublesome, and the material has to be removed by a new repair surgery, which is equivalent to nothing. In order to better achieve the safety and effect of skull repair, a new type of material is gradually promoted, that is peek material. peek is an advanced polymer material that avoids all the limitations of titanium mesh material, with good heat insulation, strength, elasticity and hardness comparable to the autologous skull, which is an excellent material for skull repair surgery at present.