With the publications of the International subarachnoid aneurysm trial (ISAT), endovascular treatment has become one of the most important treatments of intracranial aneurysms, and was used more and more in clinic settings. However, intracranial complex aneurysms (such as giant aneurysms, wide-necked aneurysms, fusiform aneurysms and dissecting aneurysms) still impose a huge challenge for clinicians. Flow diverter (FD) is a novel device for the treatment of aneurysms based on the understanding of hemodynamic mechanism of aneurysm occlusion. It could divert the blood flow from the aneurysm neck, and promote aneurysm occlusion without inserting coils into the aneurysms. In addition, the FDs had the advantage of simplifying the procedure and relieving the mass effect.