Multi-online central air conditioning is a type of household central air conditioning, commonly known as "one to many", which refers to an outdoor unit connected to two or more indoor units through piping, and the outdoor side adopts the form of air-cooled heat exchange, and the indoor side adopts the form of direct evaporative heat exchange. Multi-online systems are now being used more and more widely in small and medium-sized buildings and some public buildings. In the face of the rapid development of multi-online air-conditioning system in China, experts have first affirmed the characteristics and advantages of multi-online air-conditioning system, and believe that with its market expansion, it has a great impact on China's air-conditioning industry and energy saving, and pointed out that in order to promote the healthy development of multi-online air-conditioning system in the market, we must pay attention to the following aspects: 1. Product development must be in line with China's national conditions and reasonable application; 2. Prepare applicable standards and standardize design, construction and acceptance; 3. Enterprises improve their sense of responsibility and mission, strengthen self-discipline, and promote the healthy development of the market. At the same time, the experts also put forward suggestions for the further development of multi-connection, such as the development of multi-connection air-conditioning systems for water sources, and the promotion of the use and development of renewable energy; The formulation of national energy efficiency standards for multi-online has a great role in promoting the improvement of multi-online performance in the Chinese market, and has a significant effect on energy saving and consumption reduction.