Based on silicon Micro-Electro Mechanical System(MEMS) technology, an X-band four-channel 3D integrated T/R module suitable for array antenna system is designed. The module is stacked by three layers of chips connected to each other by Through Silicon Via(TSV) and Ball Grid Array(BGA). The module integrates functions such as 6-bit digital control phase shifting, 6-bit digital control attenuation and serial-to-parallel conversion, negative voltage bias, power modulation. The dimension of the module is 12 mm×12 mm×3.8 mm. The test results show that in the X-band, the saturated transmitting power of the single channel reaches 30 dBm, the gain of transmitting channel reaches 27 dB, the gain of receiving channel reaches 23 dB, the noise figure is less than 1.65 dB. The module bears excellent performance and high integration, which is suitable for mass production.