Abstract: During the construction process of new power systems, the installed capacity of generation units is rapidly increasing, leading to a significant surge in uncertainty on both the supply and demand sides. Consequently, the traditional mode of balancing generation with load fluctuations will struggle to meet the operational requirements of these new power systems.. Based on the actual operation conditions in recent years, this paper conducts an in-depth analysis of power balance issues such as insufficient power supply, and difficulties in the absorption of new energy caused by various factors. Then, the specific challenges are analyzed in terms of increasing uncertainty on both sides of the source and load, insufficient system adjustment capabilities, the frequent occurrence of extreme balancing scenarios, and the enhanced large-scale mutual demand. In response to the above challenges, the key control technologies that support the power balance of the new power system are introduced including the spatiotemporal collaborative balance mode with overall coordination-distributed autonomy, quantitative evaluation technology for power generation capacity considering primary energy supply, accurate prediction and regulation capacity quantification technology for load-side resources, integrated balance optimization decision-making technology for interconnected grids, the analysis of multi-cycle balance ability, early warning and pre-decision-making and the multi-scenario balance decision-making and control technology. Furthermore, a panoramic collaborative power balance decision support system based on above research results is introduced. Finally, the development of power balance in new power system is carried out from the aspects of market incentives, flexible regulation, electricity-carbon synergy and multi-energy system collaborative operation.