As a main insulating material in the DC cable attachment

silicon rubber has the problem of space charge accumulation. It is important to study the trap characteristics of silicone rubber nanocomposites for the suppression of space charge accumulation in polymer materials. Consequently

suing methyl vinyl silicone rubber as base rubber

we prepared silicone rubber samples

which doped with different content（5%

10% and 20%） of SiO

2

. The fracture surface of samples was observed by scanning electron microscope. Under the charge and discharge conditions of positive and negative corona

the potential decay characteristics of the sample were measured by an electrostatic probe. In order to obtain the hole-type trap characteristics and electron-type trap characteristics of samples

we adopted the double-trap energy model and the isothermal surface potential decay model. The resu

lts show that the hole-type traps in pure silicone rubber are mostly shallow traps

while most electron-type traps are deep traps. When the content of doped SiO

2

nanoparticles is 5%

the hole-type trap depth and trap density of the composite are more than those of pure silicone rubber. At the same time

the hole-type traps and electron-type traps are dominated by deep traps. When the content of SiO

2

nanoparticles in composite increases to 10% and 20%

the hole-type and electron-type deep traps density decreases significantly

and the surface potential is rapidly attenuated by a large number of shallow traps in the material. The results can provide some reference values for the modification of silicone rubber materials in DC cable accessories.