In 2021, China’s power generation industry took the lead in launching carbon emissions trading, ushering in a major challenge and opportunity for the sustainable development of power enterprises. Assessing the sustainable development performance of power enterprises has become the key to the sustainable financing and development of power enterprises in this new developmental stage. Based on the integration of the long-term UN Sustainable Development Goals (SDGs) and the ESG (Environmental, Social, and Governance) evaluation indicators of listed companies, this paper constructed an index system for the evaluation of the sustainable development of electric power companies consisting of 75 indicators corresponding to four dimensions: economic, social, environmental, and governance. Given the vision for the sustainable development of electric power companies, the assessment thresholds for each indicator were determined by the practical exploration and typical progress assessment of SDGs. Aggregate assessment and dashboard assessment techniques for the sustainable development of electric power companies were established, and we conducted a robustness analysis of the evaluation system. The results revealed the following details: (1) The disclosure of sustainable development indicators of Chinese electricity enterprises was 94.13%, among which the four dimensions of economy, environment, society, and governance were 99.89%, 82.62%, 94.00%, and 97.71%, respectively. (2) The aggregate sustainable development index for Chinese power companies was 59.34, and the environment, society, governance, and economic scores were 62.10, 64.49, 76.79, and 41.37, respectively. (3) Based on the results of the dashboard, investment in innovation, public welfare, emissions of greenhouse gases, and economic sustainability are the key factors limiting the achievement of sustainable development. (4) The framework’s robustness analysis showed that the results of the evaluation of this paper’s indicator framework fell within a reasonable range of variation using different ranking and weighting systems. Chinese electricity companies should comprehensively control costs and expenses, strengthen capital management, expand funding channels, focus on enhancing R&D capabilities, enhance their scientific and technological innovation management systems, and improve their disclosure of information about greenhouse gas emissions, resource consumption and use, and employee issues to improve the overall level of sustainable development. The evaluation system developed in this paper further enriches the evaluation of corporate sustainability performance. This paper explored the application of the SDG index and dashboard construction methods at the national level to the evaluation of sustainability at the corporate level, providing a clear picture of corporate performance with respect to various dimensions, issues, criteria, and indicators.