In response to the needs of hierarchy, diversity and difference in territorial spatial planning, this paper discusses the basic logic problems, application challenges and responses between resource and environment carrying capacity, territorial development suitability ("double evaluations") and territorial spatial planning. By systematically combing the theoretical development and policy response of "double evaluations", this paper summarizes the research focus and service objectives of "double evaluations" in the three stages of application exploration, connotation expansion and system support, and expounds the evolution process of the logic of capacity and suitability. Several key challenges in the application of the current "double evaluations" are sorted out. First, the logic of the application of "double evaluations" in the delineation of "three types of spatial zones and alert lines" is not yet clear. Second, there is a logical paradox between the current carrying capacity evaluation and future planning decision-making. Third, the "double evaluations" method fails to pass in the territorial spatial planning at different levels. Finally, there are still controversies on the relationship logic between the two evaluations. Therefore, this paper puts forward four suggestions to improve the "double evaluations": deepen the theoretical cognition, expand the evaluation dimensions, establish the transmission mechanism, and clarify the internal relationship, so as to enhance the support of the "double evaluations" to the territorial spatial planning decision-making.