Abstract: The rapid growth of China's power industry has provided significant momentum and unprecedented opportunities for the advancement of high-voltage organic external insulation technology. Among the key innovations in this field, silicone rubber composite insulators stand out as a typical representative, warranting detailed analysis of their development process. Through three major opportunities and four important stages, the large-scale application of silicone rubber composite insulators in power systems has enabled China to become the first country in the world to primarily utilize organic external insulation in ultra-high-voltage transmission systems. To support the construction of the new electricity system, the development of a new generation of long-service-life composite insulators has become a critical technical challenge. Therefore, this paper focuses on the technological evolution of composite insulators, providing a systematic review and summary of the development trajectory of composite insulator technology both domestically and internationally. It also offers a comparative analysis of the characteristics and key areas of focus at different stages of development worldwide. Furthermore, the paper highlights the key technological breakthroughs achieved in China in the field of composite insulators and discusses the global evolution of technology, current critical issues, and collaborative efforts across the industrial chain for long-service-life composite insulators.