The Airspace Flow Department focuses on providing a solution which could optimize air traffic flow of civil airports and airspace in their vicinity to solve the problem of flight delay and air traffic jam caused by the increasing demand on the civil aviation transportation. According to relevant national principles, rules of law as well as regulations, decisions and instructions of CAAC, by means of air traffic passage capacity assessment, we have developed and advanced classic optimization model, built up a comprehensive optimized model, integrated airports and airspace in the vicinity as one system, adjusted flights flow and airports capacity of takeoff and landing in terms of traffic requirements and containment; we aim at making optimal airspace planning in order to construct a flexible airspace structures and better distribute airspace resources, etc.