Recommendation ITU-T L.1327 describes a universal data centre-cooling technology selection method at its current industry development stage by matching detailed analysis of such technology and typical application scenarios. (1) Industry mainstream data centre-cooling system solutions are categorized and summarized, and their technical principles, characteristics and routes analysed in detail to provide a basis for technology selection. (2) The complete cooling system is then divided into a number of processing components, and key factors affecting their performance are identified by analysing their technical principles. (3) Common data centre application scenarios are then classified from different dimensions, excluding those that have little or no impact on cooling, to identify appropriate scenarios for the performance of each processing component in a cooling system. (4) Single dimensional application scenarios are integrated into those that are multi-dimensional in line with the actual situation. Corresponding cooling system processing components are then integrated into a complete cooling programme to finalize technology selection for a data centre project. Current data centre-cooling technology presents complex, diverse and fast update characteristics, there are many factors affecting actual application of cooling technology and data centres are usually faced with multi-dimensional and complex scenarios. A selection method for appropriate cooling technology in different application scenarios has become key to the safe energy-saving operation of a data centre.