Since the reform and opening up, China’s economic development has made remarkable achievements. However, the spatial problems have become increasingly prominent, such as the destruction of resources and environment, the disorder of spatial development, and the imbalance of regional development. In order to promote the coordination of urbanization development and environment protection and balanced development of regions, the idea of major function zone was established. The major function zone is an important policy tool of the system implement for developing and protecting territorial space. How to understand the major function zone and planning? It has become an important issue that cannot be bypassed in the construction of the territorial spatial planning system in the new era. This paper starts with the cognition of territorial space, discusses the connotation and existing problems of the major function zone. On these grounds, the article puts forward relevant suggestions for the future optimization of the major function zone. Based on the “region” and “element” characteristics of territorial space, this paper reviews the cognition and planning practice of major function zone. The major function zone is closely centered on the feature of the regional territorial space. 1) The ideology of the major function zone comes from the idea that “region” has dominant territorial function. In view of the macro characteristic and functional diversity of the regional territorial space, the division principle of major function zone is comprehensive. It highlights the major functions of the region and has auxiliary functions. 2) The major function zone takes “regional” territorial space as the division object. The optimized, prioritized and restricted zones basically adopt county-level administrative units as basic units to interface with the governmental responsibilities. And the prohibited zones are some special regional territorial space on a macro scale. 3) The implementation measures of major function zone planning are policy management tools targeted at “region”. Focusing on comprehensive management, the major function zone planning puts forward diversified supporting policies, and clarifies the key points of performance evaluation for different major function zones. From the perspective of “region-element” coordination, some problems are found in the planning implementation process. 1) In the transmission of “region-region”, there is a deviation between the two-level planning schemes. In the game between central and local governments, local governments hope to bring more administrative regions into prioritized zones, in order to obtain more development opportunities. In addition, the provincial planning may have incomplete understanding of indicators and policy connotations, which will lead to an inadequate implementation of superior planning. 2) In the transmission of “region-element”, a use-oriented regulation system has not yet been formed. Most of the indicators in the major function zone planning come from other planning that have been approved and promulgated. The supporting policies for regional territorial space are closely linked to the development planning rather than using control of elemental territorial space. 3) In the coordination of “region-element”, organic synergy with other spatial planning has not been achieved. In terms of content, the major function zone planning refers more to other existing spatial planning. In terms of implementation, the major function zone planning does not leave corresponding interfaces to other spatial planning. In terms of authority, the major function zone planning has not obtained corresponding legal basis and lacks mandatory binding force. Facing the requirements of the ecological civilization construction and the national space governance in the new era, this article points out that from the perspective of “region-element” coordination, it is necessary to further improve the major function zone system from the following three aspects. 1) Effectively incorporating into the territorial space planning system. This paper believes that the government should adhere to the legalization of space governance and strengthen the position of the major function zone strategy. Combine major function zone with the index decomposition, spatial regulation and other control measures apply to elemental territorial space. 2) Optimizing the existing major function zoning. In terms of function adjustment, the positioning and development direction of provincial major function zoning should be consistent with national planning. In addition, the proportion of each major function zone should be strictly controlled. When optimizing the major functional zones of coastal counties, the planning should take spatial protection and sea area development into account, with the principle of land-sea coordination. 3) Implementing the performance evaluation mechanism. On the one hand, it is necessary to strengthen the connection with other types of assessments. The government should appropriately adjust the existing assessment and evaluation indicators according to the major functions. On the other hand, the application of the assessment results should be strengthened. It brings the construction of the major functional zones into the comprehensive performance evaluation.