As an important strategy to promote the goal of "double carbon", the low-carbon transformation of energy structure needs a series of institutional measures to promote the formation of an energy structure pattern with both "clean energy use" and "energy supply". Market mechanism is the main driving force of low-carbon transformation of energy structure, and energy market access system is an important constraint and regulation tool to play the role of market mechanism in order stability and risk prevention. Therefore, the low-carbon transformation of energy structure must be implemented by building a perfect energy market access system. The traditional energy market access system has limitations on low-carbon governance. The innovative energy market access system should reflect the dual value pursuit of maintaining energy market order and realizing climate public interests, and its function is positioned in the dual structure of "prevention-control". The functional orientation of "prevention-control" calls for a clear and more scientific legislative orientation of the energy market access system. The normative construction of this system must implement different functional allocation, resource integration and legislative strategies in the "carbon source" stage and "carbon flow" stage respectively: the former focuses on adjusting the proportion of traditional fossil energy, clean energy and renewable energy in energy development and utilization, and promotes the low-carbon upgrading of energy structure; the latter pays attention to the qualification access and behavior supervision of the energy industry, and strengthens low-carbon governance on the basis of ensuring the reasonable supply of energy. From this point of view, the innovation of energy market access system should be based on the principle of unity and difference, and the system elements involved should be summarized and characterized from two aspects of energy supply and low-carbon control, so as to further improve the normative forms of access standards, licensing matters, access approval and follow-up supervision, enrich the normative content and procedural structure, and enhance the institutional capacity. In a word, first, based on the principle of coordinating energy supply and low-carbon control, pay attention to the practical orientation of standards such as qualification access, scale access and project review in different energy access scenarios, and form stable and quantitative access standards; second, based on the criteria of "the necessity of energy supply" and "the degree of carbon risk", the differentiated operational requirements and behavioral requirements are identified according to the characteristics of different energy mining enterprises and processing and conversion enterprises, and then the licensing conditions and transaction allocation of various energy industries are determined; third, based on the concept of structural connection with equal emphasis on access approval and follow-up supervision, we will build a special review mode centered on "the ability to perform access affairs and standards" and a follow-up supervision mode centered on "the effectiveness of fulfilling obligations of energy supply and low-carbon control" to strengthen the supply of energy services and the fulfillment of low-carbon obligations of the admitted subjects.