The paper aims to further explore the current situation of Chinese investment in overseas clean energy and analyze the development of the power industry in the field of clean energy. The paper elaborates the present development status of clean energy based on the Data Envelopment Analysis (DEA) model and investment efficiency theories, analyzing the potential risks taken by China’s electric power industry from the investment in overseas clean energy and calculating the power enterprises’ investment efficiency. The results reveal that China’s overseas investment in clean energy has developed rapidly. However, from 2016 to 2017, due to the accelerated investment in clean energy, the comprehensive investment efficiency of clean energy has dropped significantly, to 79.1% and 78.7%, respectively. Subsequently, the comprehensive investment efficiency increased significantly, reaching 80.4% in 2019. Between 2015 and 2019, effective investment in clean energy has reached the highest, 32% in 2015, while there are more ineffective investments in 2016. After 2017, the proportion of power enterprises’ investment in clean energy has increased significantly, accounting for 32% in 2019. In future development, the proportion of investment in this field will continue to rise. Hence, clean energy boasts good development prospects.