As one of the main profession, the level of digital design in the electrical system will be an important component of the digital design capabilities in nuclear power plant (NPP). This paper analyzes the background and current situation of digital transformation about the electrical design of NPP, clarifies the necessity of developing an integrated electrical system design platform (hereinafter referred to as the ‘Electrical Platform’) suitable for nuclear power engineering, which integrates all electrical design and design management functions. The functional requirements, non-functional requirements of Electrical Platform are proposed. Considering the advantages and disadvantages of different architectural patterns, the system’s architecture design of the Electrical Platform is designed into C/S (Client/Server) and B/S (Browser/Server) hybrid mode, and relevant key technologies for this system are proposed. Ultimately, the development of the Electrical Platform is completed and tested in conjunction with actual engineering projects. The test results demonstrate that the platform effectively enhances design quality, improves work efficiency, strengthens business capabilities in electrical design for nuclear power projects, and achieves favorable benefits and positive impacts. The development model and application results of the platform hold great value for reference and promotion.