The main problem explored in this study is how Taiwan and other countries meet the challenges of the United Nations Sustainable Development Goals regarding energy transition by using legal instruments or policy bundles. This study adopts textual analysis and legal policy analysis as its main form of research methodology, and the theory of energy justice, as well as principles of energy management, to correlate with the Sustainable Development Goals. Furthermore, this study aims to construct an analysis structure for national energy transition and to analyze the current situation within Taiwan’s electricity sector reforms, while providing evidence of the national experience of electrical industry reforms as an international reference. This study also compares the differences between the seventh Sustainable Development Goal relationship and national energy transitions in Taiwan and Japan, based on the similar initiative of the revised Electricity Act with the policy bundle. This study specifically finds that, firstly, the theory for energy justice is connected with the principles for energy management, owing to the same concepts of “Fair Competition”, via the recognition of “Energy Development and Poverty”, which correlates with “Environment Protection”. Therefore, the concept of energy transition proposed in this study integrates national energy development policy goals and combines them with environmental sustainability, the green economy, and social equity. Secondly, the national energy transition in Taiwan is a response to the Sustainable Development Goals, and electricity sector-related laws could be used as legal tools for national energy transition. This study concludes that Taiwanese and Japanese governments can strengthen their environmental regulations to promote fair competition directly, with fair competition then being able to enhance stable electricity supply, to enable these countries to move towards the seventh Sustainable Development Goal and its indicators. Finally, the analysis structure used in this study could be used as a policy analysis tool for other countries during their own energy transition, when a nation is willing to strategically reform its electricity sector and make sustainable choices regarding transition paths and policy bundles that are suitable for the situation of the individual country. Then, a nation can make revisions to its laws and formulate a policy that is in line with local conditions, while as simultaneously implementing the Sustainable Development Goals.