In this paper, we propose and discuss a new excitation model for low-frequency electromagnetic induction. First, the hardware principle and frequency domain mathematical expression of the model are given, and then the gain equation with the traditional RLC resonance model is obtained. In order to accurately obtain the inductance of the excitation winding under different structures, the factors affecting self-induction and mutual inductance of the solenoid multi-layer winding are analyzed in detail. Finally, through reasonable assumptions and the characteristics of inductance processing, the gain equation is necessary to be deformed and simplified, and is directly displayed in the three-dimensional surface graph.