The interface between cable and accessory（a terminal or a joint） is always the weakest point of cable due to the space charge accumulation driven by direct current（DC） voltage combined with influences of temperature. Therefore

we measured the space charge characteristics of silicone rubber（SR）/cross-linked polyethylene（XLPE） double-layer dielectrics under working DC electrical stress based on temperature effect in the running DC cable system. Moreover

we established a model of accessory fitted on cable according to the measured results and the relation between resistivity and temperature

and discussed the effect of space charge on field distribution at the insulating interface between DC and accessory under temperature gradient. The test results show that space charges at the interface between cable and accessory increases with temperature gradient（temperature difference）

which enhances the electric fields near the stress cone at the SR/XLPE interface. On the other hand

under temperature gradient

the space charges contribute to slightly weakening the field near the stress cone

but slightly enhancing the field near the high voltage shielding tube.