Styrene acrylic resin is the main component of toner. The thermal conductivity of toner could be improved significantly by increasing the thermal conductivity of styrene acrylic resin. Then, the life of printer and copier could be extended. By adding single or hybrid high thermal conductivity fillers of carbon nanotubes and graphene into styrene acrylic resin, a connected thermal conductivity network was constructed in styrene acrylic resin to improve the thermal conductivity. When 0.75wt% multi-walled carbon nanotubes (MWCNTs) were added into styrene acrylic resin, the thermal conductivity of styrene acrylic resin composite was increased from 0.1252 W/(m?K) to 0.1644 W/(m?K) with an increasing of 31.31%. When 1.0wt% MWCNTs-COOH was added into styrene acrylic resin, the thermal conductivity of styrene acrylic resin composites was increased to 0.1751 W/(m?K) with an increasing of 39.86%. When MWCNTs-COOH and graphene were added into styrene acrylic resin, the thermal conductivity of styrene acrylic resin composites was increased to 0.2093 W/(m?K) with increasing of 67.17%, which indicated the hybrid fillers (MWCNTs-COOH and graphene) formed connected thermal conductivity network in styrene acrylic resin. Thus, the thermal conductivity of styrene acrylic resin composite was improved significantly.