Abstract: In context of rapid development in modern agriculture, efficient operation of multi-span greenhouses holds great significance for agricultural production．Traditional greenhouse heating and cooling systems are plagued by high energy consumption and low efficiency．To improve greenhouse energy utilization efficiency and environmental control levels hinges on integrated design and application of new water source heat pump systems with new technologies．Multi-span greenhouse in Beijing Academy of Agriculture and Forestry Sciences was taken as research object．Fundamental principles of water source heat pump technology were in-depth analyzed, and an efficient water source heat pump system scheme integrating new technologies has been designed．Key elements of system design were thoroughly explored, including system architecture construction, heat pump units selection, water source system design, and energy-saving benefits evaluation．At the same time, integration application of new technologies such as internet of things and intelligent control was comprehensively considered．Research results showed that system not only effectively met temperature control requirements of multi-span greenhouses, and accurately adjusted environmental parameters in real time, but also significantly reduced energy consumption．A scientific and effective solution for water source heat pump systems design in multi-span greenhouses was provided, which would help to promote modern greenhouses development towards energy-saving and intelligentce, and would offer valuable references for water-source heat pump systems innovative design and application．