With the rise of XLPE insulated DC cable voltage level, the requirements on the quality and reliability of semi-conductive shielding material are increasing. In this paper, two imported and one domestic high quality HVDC semi-conductive shielding materials in combination with one domestic XLPE DC cable insulation material are selected for testing. Their thermal, electrical properties, shielded and insulated composite performance are tested. The effects of DC cables shielding materials on space charge in XLPE insulation are analyzed. On the basis of these results and analysis, the filling amount and particle size of carbon black, the matrix resinare and interface bonding are proposed to be the key factors which affect the volume resistivity and space charge of semi-conductive shielding materials.