Structural feature extracting, recognizing and understanding of a military airfield image is an enormous project. This process runs through the low, middle and high level image processing of image understanding system (IUS). For the time being, all the researchers in the recognizing and understanding method of an airfield are mainly focusing on the recognition of airfield runways, without considering other facilities in the field. The image of the facilities such as roads, hangars, connective paths, and bullet-proof bunkers are also the needed information, since they form the whole geometric structure of an airfield with airfield runways. In addition, some methods focusing on the geometric structure of an airfield have disadvantages as long runtime and complex algorithm. Therefore, there is a need to find a new method of military airfield image recognizing and understanding. The main method we adopted in this paper is the classical refinement algorithm proposed by Hilditch firstly. This study helps to extract the useful information in a military airfield image. The main feature of our method is that it uses the geometric structural feature of a military airfield to achieve the recognizing and understanding process. The theoretical and experimental results presented in this paper show that our method has many practical values that can improve the efficiency and accuracy of military airfield recognizing and understanding.