CO2 mitigation roadmap is important for the total amount control of CO2 emission. However, as the connection and priority are being absent in some present CO2 mitigation roadmaps, technology policies may sometimes be invalid or unable to reach the mitigation target. Therefore, this research explores an innovative method of Backcasting Model (BCM) which is helpful to solve the problems. Since the Power industry is the essential department to realize the peak target of greenhouse gas emission in 2030 for China, the research takes the power industry as an example to analyze the CO2 mitigation roadmap based on BCM. According to 2020 and 2030 mitigation targets, this research selects 13 power generating technologies and calculates their implementation scales. Concrete timelines of 70 direct and indirect CO2 mitigation measures related to these technologies are derived, in which CO2 mitigation roadmaps from BCM are distinguished in terms of technique choices and implementation periods. Moreover, various types of accelerating measures provide different acceleration rates to the related direct measures. This study evaluates the feasibility and practicality of realizing mitigation targets by the 2020 and 2030 deadlines under present technologies and policies, and introduces options and roadmaps with high enforceability through the Backcasting Model.