A dry desulfurization and urea solution direct injection denitrification device for flue gas of a sintering machine comprises the sintering machine, an air bellow, an online flue gas monitoring control device, an electric air inlet valve, a reaction tower, a bag-type dust collector, a fan and a chimney. The device is characterized in that the sintering machine is sequentially connected with the air bellow, the online flue gas monitoring control device, the electric air inlet valve, the reaction tower, the bag-type dust collector, the fan and the chimney, an electric flow regulating valve is connected between the air bellow and the online flue gas monitoring control device, the online flue gas monitoring control device is connected with a PLC (programmable logic controller) control box connected with a variable-frequency rotary feeder, the upper side of the variable-frequency rotary feeder is connected with an electronic screw scale connected with a discharger, the discharger is connected with a urea granule bin, and the lower side of the variable-frequency rotary feeder is connected with the upper side of a jet flow mixer. With the adoption of the device, harmful pollutants such as SO2, NOx, dioxin, heavy metals and the like in the flue gas of the sintering machine can be removed, up-to-standard emission of the flue gas is realized, and environmental pollution is avoided.