Abstract: Based on low-frequency partial element equivalent circuit (PEEC) method, the current and potential distribution of the ground loop is presented, and the mechanism of common ground conduction interference is analyzed in this paper. Our proposed low-frequency PEEC model is achieved based on mixed potential integral equation (MPIE), and its accuracy is verified by comparing with the results of boundary element method. By realizing the three-dimensional current distribution calculation with the PEEC model, the current distribution of a typical large conductor ground loop and the effects on the current distribution due to frequency are achieved. The results demonstrate that current distribution of ground conductor is mainly concentrated in the vicinity of the ground electrode, and a potential difference is observed between two ground electrodes because of the influence of inductance, which reveals the mechanism of common ground conduction interference in the ground loop.