The invention discloses a coal-derived reducing gas base shaft furnace direct reduction metallurgical method and a system thereof. Reducing gases with CO and H2 serving as the main components are prepared from coal through a coal-derived reducing gas system, and are treated by the reducing reaction with iron ore through a direct reduction metallurgical system. The reducing gases are mainly used as the reducing agents of the reducing flow, the cooling agents of the cooling flow and the fuel of the direct reducing metallurgical system. The reducing flow is composed of a reducing shaft furnace, a furnace top gas heat exchanger, a furnace top gas shock chilling/scrubbing system, a process gas recycle compressor, a compressor secondary cooler, a CO2 absorber, a process gas humidifier, a process gas heater, etc. The conical part of the lower part of the shaft furnace is the cooling zone of the shaft furnace direct reduction metallurgical furnace. The cooling gases are sprayed in from the conical region of the lower part of the shaft furnace direct reduction metallurgical furnace, and flow upwards across the metallurgical furnace. The hot cooling gases flow away the cooling region and then are cooled, compressed and recycled. The system is simple in structure and low in process cost.