An admittance measurement instrument of piezoelectric transducer based on FPGA and ARM was developed in this work. The principle of vector voltammetry for impedance measurement was introduced. Considering the equivalent circuit of piezoelectric transducer, the transducer impedance measurement method was analyzed. The DDS signal generating circuit based on FPGA and the phase sensitive detection circuit were designed. The equivalent parameter calculation and admittance circle display were realized by using the ARM system. The experimental result shows that the proposed device has the features of simple structure and reliable measurment accuracy, and can satisfy the requirements for engineering applications.