Abstract: With the development of power electronic devices and the progress of technology, more and more high-power power electronic devices are used in power system flexible DC transmission, in order to improve the stability of power grid and the ability to accept new energy. Chongqing Hubei flexible DC back-to-back interconnection project is a typical application of this technology. However, due to the DC link and the new energy generation process contain a large number of power electronic switching devices and power modules, it brings great difficulties to the analysis of AC-DC hybrid simulation system with large-scale new energy access. Based on the concept of digital twin, MMC sub module switch device is equivalent to its turn on and turn off resistance. According to the specific parameters and network structure of AC & DC hybrid power grid in Northeast Chongqing, considering the recent wind power planning in the region, based on the analysis and prediction of load and wind power output, a set of digital twin platform of AC & DC transmission system with large-scale wind power access is established and the platform running results are compared with the actual results, which proves the effectiveness of the analysis architecture proposed in this paper.