The invention provides an energy-efficient hard carbon black reaction furnace, a conical air acceleration guide cylinder is coaxially arranged on a straight pipe section of a combustion chamber, a small opening of the conical air acceleration guide cylinder is located on one side of a throat pipe section, eight air inlets are formed in the side wall of a large opening of the conical air acceleration guide cylinder, a plurality of air outlets are formed in the surface of the inner wall of the conical air acceleration guide cylinder, a fuel inlet is formed in the central axis of the straight pipe section of the combustion chamber, four raw oil nozzles and six raw oil nozzles are arranged in the positions of the middle section and the tail end of the throat pipe section in a correspondingly staggering manner, and the raw oil nozzles in the positions of the middle section and the tail end deviate by 10 degrees from the radial axis. The energy-efficient hard carbon black reaction furnace has the advantages that firstly while the conical air acceleration guide cylinder is used for uniformly distributing the air and pressure, the air outlets in the second half section of the conical air acceleration guide cylinder are inclined, the axis intersection positions of the inclined air outlets are located on a burning airflow, the temperature can be improved and the flow rate of the burning airflow is accelerated favorably, the raw oil shear force is improved, and the splitting rate is increased.