Based on the development platform Quartus II, in which FPGA（EP1C3T144C8）is held as the core, a hierarchical design method is adopted to make three - phase sinusoidal signal output, frequency modulation and amplitude modulation available, so as to form a signal source with functional diversity, expansibility and upgrade capability by designing ASK digital modulation demodulation. The design requirements are met through functional simulation and testing. The system circuit, with its simplicity, reliability, low cost and upgrade flexibility, has some application space in the field of electronic measurement and communication.