Abstract: Under the background of the energy transition, the characteristics of the high proportion of renewable energy and the high proportion of power electronic equipment integrated into the new power system will profoundly change the form and operation characteristics of power grid, and put forward new requirements for the simulation theory research and advanced simulation tool research and development. This paper investigates the needs and challenges of the existing simulation software and simulation system in dealing with the change of stability characteristics of the new power system, the increase of time-space scale and span of simulation analysis, and the construction of the power grid intelligent analysis operation control system in the process of digital development of power systems. The characteristics of existing simulation technologies are analyzed, and the shortcomings of current simulation tools are pointed out. Finally, the development trend of simulation tools is clarified, a simulation technology framework for the new power system is proposed, and the potential technical development points that simulation tools need to pay attention to are prospected.