###### Abstract
However, in terms of geophysical exploration, only AMT (audio-frequency magnetotellurics) surveys and 1:500,000 gravity exploration studies ([PERSON], 2019) have been carried out in different sections of the Jinding lead-zinc deposit; thus, systematic geophysical research is lacking [9]. In particular, the current success rate in exploring middle-to-deep concealed ores remains low, and mining enterprises are already facing a resource crisis. Therefore, further research on geophysical exploration methods and techniques for the Jinding deposit is essential to establish  
Figure 1: Simplified geological map of the Jinding mining area, Yunnan Province. effective geophysical exploration models and prospecting strategies for future mineral resource exploration. The controlled-source audio-frequency magnetotellurics (CSAMT) method, renowned for its robust anti-interference capabilities, extensive detection depth, and remarkable work efficiency, has emerged as a pivotal tool in deep resource exploration. Its applications (such as in [PERSON], 2010; [PERSON]; [PERSON], 2016; [PERSON], 2016) have yielded outstanding outcomes in mineral resource exploration, concealed ore body identification, and metallogenic prediction within complex geological terrains [10; 11; 12; 13; 14]. Therefore, based on the exploration objectives and requirements for the concealed ore bodies in the middle and deep parts of the mining area, the CSAMT method can be selected as the geophysical exploration approach for the Jinding lead-zinc deposit. By combining this with a geophysical model of the deposit, forward numerical simulations can be utilized to verify the effectiveness of the exploration method. At the same time, based on the forward simulation parameters, a geophysical technical solution suitable for exploring ore bodies in the Jinding deposit can be selected and optimized. For general geoelectric models, CSAMT methods do not have simple numerical solutions and often require reliable numerical solutions to be sought. Traditional methods for solving CSAMT numerical solutions can be summarized into four main algorithms: the volume integral method, the boundary integral method, the finite difference method, and the finite element method. The finite element method has been adopted by many scholars ([PERSON] 2018; [PERSON] 2014, [PERSON] 2012, 2014, [PERSON] 2014, [PERSON] 2014, [PERSON] 2015, [PERSON] 2016) due to its characteristics such as grid diversity and high calculation accuracy [15; 16; 17; 18; 19; 20; 21; 22]. However, these studies share a common characteristic: the finite element calculations predominantly adopt traditional truncated boundaries, which approximate infinite boundary problems within a relatively large region as finite ones. This approach often leads to issues such as large calculation areas, high node counts, significant storage requirements, and time-consuming computations. A more reasonable boundary-handling strategy should limit the calculation area to a smaller target region, reducing the number of elements and nodes and thereby conserving computational resources and improving computational speed. The finite element-infinite element coupling method offers the possibility to implement this strategy. The core idea of finite element-infinite element coupling is to replace traditional truncated boundaries with \"infinite elements.\" By using coordinate mapping, \"infinite elements\" are infinitely extended in a certain direction, enabling the electromagnetic field to rapidly decay to zero within these elements. Finally, by combining finite elements to discretize the internal small region, rapid forward simulations can be achieved [23; 24]. In the field of geophysics, the infinite element method is primarily applied in seismic exploration, well logging, and direct current (DC) resistivity methods. [PERSON] (2019) successfully implemented this technique in numerical simulations of DC resistivity [25], but its application remains relatively limited in electromagnetic methods.