Abstract: The Chinese government has clearly put forward the "two-step" goals of carbon peaking by 2030 and carbon neutrality by 2060. As the capital of China, Beijing needs to take the lead in achieving the carbon peak; and provide a reasonable and feasible scientific methodology to optimize the carbon peaking path. In order to explore the timetable and roadmap of Beijing carbon peak, the study carried out simulation prediction research from the perspective of dual control of structure and efficiency, innovatively developed the Beijing Carbon Peak Simulator, and utilized policy dynamic simulation as an approach to achieve 2020—2035 simulation of Beijing's economy-energy-carbon development. The simulation results show that when structure and efficiency are combined, Beijing's carbon peak can be achieved in 2027, significantly reducing the peak carbon emissions to 147.55 million tons. Under the dual control circumstance, the proportion of new energy in the peak year reaches 12.1%, and it will increase year by year to 31.4% in 2035, and the overall energy efficiency can be improved by 51%. Among the three major measures, the marginal emission reduction effect of the optimization of structure is more significant in the early stage, and the marginal effect of energy efficiency improvement in the later period of peaking is more obvious.