Abstract: In August 2022, Sichuan suffered a wide range of long-term extreme high temperature and drought weather, thus facing the "Three Most" superposition of the situation; that is, the highest extreme temperature, the least precipitation, and the highest power load. The substantial reduction of hydropower and the sharp rise of load have resulted in a large power supply and demand gap, which led to severe emergency electricity curtailment event. This event caused widespread concern in the industry. Therefore, this paper analyzes the key influencing factors of the Sichuan electricity curtailment event from the perspective of extreme high-temperature and drought weather, and focuses on an in-depth analysis of Sichuan's flexibility resources including power generation, network, load and storage aspects. Secondly, the multi-dimensional characteristics of the new-generation power system such as generation-side randomization, network-side interconnection, load-side electrification, flexibility-side marketization and operation-side intelligentization are summarized from the power supply dimension. Furthermore, from planning, operation, trading and policy perspective, the electricity supply challenges faced by the new-generation power system integrated with an increasing proportion of new energy such as wind power and photovoltaic power are analyzed. Finally, the corresponding countermeasures, solutions and suggestions are proposed for the above challenges in terms of planning, operation, trading and policy to provide power supply guarantee ideas for new-generation power system.