The difference in conductivity between the reinforced insulation material and the cable main insulation material affects the electric field distribution in high-voltage direct current（HVDC） cable terminal. So

silicone rubber composites with conductivity nonlinearity were prepared by adding nano silicon carbide

nano-silica

nano-carbon black and nano-graphite to the silicone rubber. The effects of the types and contents of nanofiller on the DC conductance characteristics

DC breakdown characteristics and dielectric spectroscopy properties of the silicone rubber nonlinear composites were investigated experimentally. Under the influence of temperature

the electric field simulation was carried out by using COMSOL Multiphysics simulation software to analyze the influence of the nonlinear conductance characteristics of the reinforced insulation on the electric field distribution of the high-voltage direct current（HVDC） cable terminals. The results show that

when the silicon rubber composite material doped with graphite/carbon black（5/3）is used as the reinforced insulation of HVDC cable terminals

the electric field distribution of the HVDC cable terminals can effectively be improved.