The invention provides a method and device for preparing continuous high-electric-conductivity and high-thermal-conductivity carbon fibers. The device mainly comprises four parts for conducting a degumming process, an impregnation/atomization spraying process, a drying process, a high-temperature shaping process and a winding process, wherein in the degumming process, the effect is mainly achievedthat slurry agents on the surfaces of finished carbon fibers are removed at high speed; in the impregnation/atomization spraying process, the effect is mainly achieved that coating treatment of shaping agents is conducted on the surfaces of continuous carbon fiber filaments; in the drying process, the effect is mainly achieved that the surfaces of the carbon fiber filaments are quickly dried after the coating treatment of the shaping agents is conducted; in the high-temperature shaping process, specific continuous heating equipment is mainly utilized to conduct high-temperature shaping treatment on the carbon fibers to achieve the preparation and surface optimization of the high-electric-conductivity and high-thermal-conductivity carbon fibers; a winding device achieves the operation of collecting the carbon fibers by adopting the continuous cooperation of a tension system and a rolling system. By means of the device and the preparation technology, the production of the continuous high-electric-conductivity and high-thermal-conductivity carbon fiber filaments is achieved, and production and processing of different linear carbon fiber filaments can be carried out.