Abstract: The low-carbon transformation of global energy sector continues to deepen, and technological innovation and technological competition continue to heat up. The dual carbon transformation is not only a historic opportunity for China to fulfill the responsibility of a big country, realize technological and industrial upgrading, and realize control over national energy security, but also a huge challenge to the traditional energy system dominated by fossil energy. The energy transformation process faces the “Impossible Triangle” problem of multi-objective trade-offs of greeness, economic efficiency and security requirement for a long time. Therefore, it is necessary to build a “1+N” dual carbon policy system to overcome the limitations of a single emission reduction policy. The construction and improvement of the “1+N” policy system needs to grasp its internal characteristics: multi policy interaction, rich micro characteristics of the participants, and complex transformation risks. Grasping the internal characteristics is the key to the construction of the policy system. This paper summarizes the research progress in key problem areas. According to the two main methodological lines of policy empirical evaluation and policy simulation, it is proposed that only through the combination of ex post evaluation and ex ante simulation, and the combination of traditional methods and the new approaches such as big data, can we better build and improve the dual carbon “1+N” policy system, and promote the smooth realization of the huge changes faced by China's social economy in the process of dual carbon transformation.