An electromagnetic interference(EMI) filter with the function of separating working and noise current is proposed based on the ″skin effect″ and ″proximity effect″. By plating a high loss conductor with a certain thickness to the outside of the unit, the common mode (CM) noise can be dissipated due to the skin effect. While by plating the conductor to the inside of the unit, the differential mode (DM) noise can be dissipated due to the proximity effect. By proper electrical connection, the ″noise″ current and the ″working″ current can be separated,thus achieving the suppressed high frequency noise current and almost lossless working current. Based on the finite element method (FEM), the harmonic field model is established, the current density distribution is simulated, the AC resistance coefficient is extracted, and the quantified analysis of the dissipation capability is included.