The invention discloses a carbon fiber middle sizing drying device, and belongs to the technical field of carbon fiber production equipment. The drying device comprises a sizing device, a drying device, and a drawing device of the sizing device and the drying device passed through by a drawing tow. The sizing device comprises a sizing roller, a drive device for supplying power to the sizing roller, and a thermal insulation interlayer. The drying device comprises a drying furnace provided with a temperature sensor, a gas storage heating tank connected with the drying furnace through a thermal pipeline, and a gas drive control valve connected with the gas storage heating tank through a gas inlet pipe. The carbon fiber middle sizing drying device can independently adjust the marching speed of the tow, the sizing speed, the drying temperature and the gas flow speed and the like factors in the sizing process, can simulate high performance carbon fiber production processing of varying grades, and facilitates the coordinated control of the whole processing process, and can obtain technical information closer to production realities in the process of adjusting the processing parameters or of manufacturing different property and different grade carbon fibers.