Abstract: An integrated design method of digital twin system is proposed to meet the practical application under real working conditions in this paper. Firstly, the functional requirements of the valve-side bushing digital twin system are analyzed. Based on these requirements, the framework of digital twin system is constructed. Secondly, the implementation methods corresponding to the digital twin system framework are designed and developed. Finally, the application of a valve-side bushing digital twin system is used to demonstrate and validate the proposed method. This method provides a design concept for the practical application of digital twin systems and can offer practical and effective solutions for the digital transformation of power grids.