The implementation of hardware and software in communication and control circuit of a navigation simulator is described. The complicate UART communication and the control of RF unit and waveform unit are implemented by only use of FPGA, making the circuit more stable and efficient. The hardware in the system is XC4VLX40 chip manufactured by Company Xilinx; the software in the system is VHDL and a design tool Xilinx ISE9.1i.