The traditional airspace theory is faced with a series of problems such as the rapid growth of traffic density and the complex multi-class heterogeneity of the airspace controlled objects. Therefore, it is urgent to make research on the digital modeling of airspace and develop a new four-dimensional space-time framework of air traffic, then to launch a new collaborative management of airspace and air traffic flow on this basis. This paper focuses on the summary of the horizontal grid model and the three-dimensional airspace grid model, and surveys the research on the application of airspace grid method in air traffic management. On this basis, the research emphasis and development trend of the airspace gridding and digitalization are comprehensively analyzed. The research results aim to provide scientific guidance for the sustainable development of theory and application for airspace gridding and digitization.