The invention discloses an extensible highly-integrated active phased array antenna. The antenna basically comprises an antenna array plane, a thermal control structure, a TR module array, a secondary feeding network, a primary feeding network, a power module, and a wave control module. The antenna is implemented by the following scheme: the TR module array is designed into a brick type linear array, eight-channel TR modules are used as sub arrays of the linear array, and the TR module array is expanded according to the integral multiple of the eight-channel TR modules; the antenna array plane, the thermal control structure, the secondary feeding network, the primary feeding network, the power module and the wave control module are stacked like tiles; a low-frequency flexible connector integrates power supply to the TR modules and feeding of on-off, phase shift, attenuation and other low-frequency control signals, and realizes highly-integrated cable-free vertical interconnection of low-frequency feeding between the TR modules and a power supply and the wave control module. In addition to the advantages of high power and large scanning angle possessed by the traditional brick type architecture, the extensible highly-integrated active phased array antenna has the advantages of low longitudinal profile height, high degree of integration, small insertion loss, and two-dimensional extension possessed by a tile type architecture.