In this paper, A compound air conditioning system energy saving scheme for the lithium battery industry is proposed. The composite air-conditioning system combines free cooling system, water-water heat pump simultaneous cooling and heating technology, frequency conversion technology and variable flow technology. Taking the project of a lithium battery manufacturing plant in Jiangsu as an example, this paper compares the operation results of the compound air-conditioning system and the factory's original distributed air-cooled screw refrigeration system + direct-fired dual-effect lithium bromide system. The results show that the composite air-conditioning system has achieved an annual energy saving of 51%, reduced energy costs by 4.62 million yuan, and reduced carbon dioxide emissions by 1,200 tons. The successful application of the project provides an attractive solution for the energy efficiency improvement of similar projects and the design of high-efficiency power station buildings for new projects.