In order to automatically connect the microwave communication link between the calling party and the called party in the low orbit satellite communication network, a specialized microwave PBX needs to be built to achieve this function, and the microwave switch array adapter is a key component of the equipment. The adapter modular is designed on the PXI bus, and its system controller accesses the local I/O adapter that follows the ISA bus specification through the PCI bus bridge, realizing the on/off control operation and telemetry status detection operation of the microwave switches. The PCI bus bridge is implemented using low-cost PCI9052, while the local ISA bus logic signal generation and I/O adapter circuit are programmed using a domestically produced FPGA circuit. After the modular development was completed, the main functions and performance were tested in the laboratory, which met the expected goals.