Abstract: The digital transformation for the Next Generation of Power Systems urges its core equipment to possess measurable and visualized status, along with detective and controllable risks. Represented by Digital Twin (DT), the digitalization and informatization technology for the new generation of power equipment has been widely proposed. Yet, the visualized real-time diagnosis and the pre-warning technology catering to transparent internal equipment characteristics still require in-depth development and further upgrading. Therefore, by proposing the connotation characteristics of the real-time interaction response between the perception network module and the simulation system of the power equipment, this article aims to analyze the difficulties and key points of the digital simulation part in DT technology. The research status of various key technologies is comprehensively elaborated, including model-driven and data-driven fast-forward calculation, inversion simulation assessment, perception network deployment, and high-precision-low-latency visualization of results. Moreover, the urgent problems within the DT system have been pointed out and investigated, including simulation efficiency, inversion calculation accuracy, perception system, inversion calculation matching, mechanism, and data fusion. Through digging into the principal difficult points within DT technologies, this work provides references and support for developing and applying digitalization in power equipment.