The noise from the converter station will have a negative impact on the residents' lives and the ecological environment. It is currently known that the main sources are filter capacitors and reactors. Taking a filter capacitor as an example, a large number of tests are required to predict the capacitor noise based on a traditional capacitor analysis modeling method, and the simulation calculation requires a huge amount of calculation power. This paper proposes an equivalent source method (ESM) based on the Huygens principle. By constructing multiple point sound source models, the acoustic characteristics of the actual capacitor are simulated and the original sound field is reconstructed. Comparison between the proposed model and the traditional boundary element method (BEM) model has been made through physical testing and simulation, and the accuracy of this method is verified.