Abstract: A new air-liquid mixed heat dissipation system is designed for an active phased array antenna in this paper. The heat dissipation system not only solves the problem of high heat-flux heat dissipation of phased array antenna, but also realizes the integrated design of antenna array. According to the technical requirements of thermal loop control of the air-liquid mixed array, the design process of the antenna array heat dissipation system is analyzed from the whole process including array system layout, thermal design, thermal simulation optimization and so on. Finally, the feasibility of the air-liquid mixed heat dissipation system of the antenna array is verified by real products, which can provide engineering reference for subsequent design of antenna array heat dissipation system.