Abstract: During the century of development of national defense economics, various of well-known national defense economics theories and experts have emerged, and their core ideas are constantly evolving with the development of the times. By summarizing and combing representative achievements in the field of defense economics, the evolution of defense economics thought is divided into three stages: war economics, early defense economics, and contemporary defense economics. It’s found that during the war, the core idea of war economics was manifested as using the economy to serve the war, during the “Cold War” period, the core idea of national defense economics was how to optimize the allocation of defense resources; during the period of peace and development, its core idea had changed to realize the coordinated development and mutual promotion of national defense and economy. This shows that national defense economics is continuously moving toward the economic track with the theme of resource allocation efficiency from its beginning of the war-oriented thinking at the time of birth. It is precisely because national defense and economy, as the process of contradiction between the two sides from opposition to unity, has promoted the continuous development of national defense economics. For our country, it should be rooted in our country's specific national conditions and view the ideological achievements of western defense economics dialectically. Then we should make full use of them in the course of coordinated development of our country's national defense construction and economic construction, and create a development road of national defense economic with Chinese characteristics.