Abstract: Aiming at the problem of fast impedance modeling of the giant magnetostrictive transducer, the modular multi-field coupling circuit simulation model and impedance modeling method are studied. The realization circuit of each component of the transducer is established according to the wave theory, piezomagnetic equation, and the mathematical analogy of electromagneto-magneto-mechano-acoustic. The corresponding module library of the core component of the giant magnetostrictive transducer is created in LTspice software, and the module library is invoked by taking a high-power giant magnetostrictive transducer with a resonant frequency of about 1 kHz as an example. The simulation model of a multi-field coupling circuit with loss is established. The impedance measurement experiment platform is built to measure the impedance characteristics of the transducer under different prestressed conditions in the air, and the underwater performance of the transducer is tested. By comparing the simulation results with the experimental results, it is verified that the impedance modeling method proposed in this paper can accurately predict the impedance characteristics and the emission current response of the transducer.