The uneven current distribution between layers of high temperature superconducting( HTS) cable is one of the key problems of superconducting cable research. Adjusting the electromagnetism structure is a effective way to balance the current between the layers. In this paper,we built the circuit matrix equation of the cable body,analyzed the current in conducting layers as well as the magnetic field it generated,gave the expressions of the self-inductance and the mutual inductance of the conducting layers. Ba...