Abstract: The conflict between Russia and Ukraine has brought profound changes to the European energy market, and the security of the electricity supply of the UK national grid in the winter of 2022-2023 has been severely challenged. Before the arrival of winter, the UK power grid has fully considered the extreme situation of the blocked supply of primary energy and the uncertainty of the power support capacity of the European continent, and put forward targeted countermeasures, which are released to the society in the annual report on the preparations for the peak of winter power demand, achieving positive results. From the de facto situation of separately-operated source and grid, gradually-matured power system and mechanism, and occasional conflicts in regional supply and demand structures in China, this kind of analysis of energy and power supply based on grid enterprises is very necessary, and it can provide sufficient reference for guaranteed power supply under the construction of new power system in China, in terms of the analysis paradigm of extreme scenarios, adequate reserve of emergency resources, and timely release of public information. It is suggested that the various source-grid-load players in market and the government departments work together, and achieve further progress in the operation simulation of power system under extreme conditions, the preparation of demand-responsive resources and the improvement of information transparency.