For a long time, due to China's defensive national defense policy, in the design of theater space, it is basically based on local and offshore defenses, and it is built in accordance with the model of "guarding the territory and defending the territory. " The military tentacles rarely extend beyond the territory. The crisis of development will be far greater than the crisis of survival. To meet the new requirements for maintaining national security and development interests, peripheral, overseas, and new security areas should be included in the theater's strategic scope, and the theater's mission functions should be further expanded to make it more outward-looking. Openness and enthusiasm. Especially with the rapid development of multipolarization, globalization and informatization, the national traditional security field has begun to expand into space, network, information, electromagnetic and other fields. Space expansion and extension, focusing on forming a strong and powerful multi-dimensional three-dimensional theater space situation. The text is intended to show that my country:. ['The scope of national defense should be expanded.', 'National Defense faces a severe development crisis.', 'New challenges in the field of traditional security.', 'The strategy of defense theater must conform to the requirements of the times.']