Abstract: To address the key issues in marine geomagnetic field modeling, this paper systematically explored the theoretical basis, modeling method, and optimization strategy of the equivalent source technology. By analyzing the geometric parameters and spatial configuration strategies of equivalent sources, a terrain-following vertical hexahedral equivalent source configuration scheme was proposed, significantly enhancing the accuracy of magnetic field models. In terms of algorithm implementation, a sliding window-based coverage calculation scheme was employed, effectively overcoming the bottleneck in the high-precision processing of massive magnetic survey data. Experimental results show that maintaining an overlap rate of 15%~20% in the sliding window ensures both boundary continuity and optimal computational performance. This method provides a reliable technical support for high-precision marine geomagnetic field modeling, with its effectiveness having been verified across various geological models (with the errors less than 5%).