The invention discloses a waste gas treatment device of a granulator, which comprises a box body, a partition, a fan, a waste gas inlet, a pipe box, a ventilation pipe, an air guide plate, a windmill, a perspective plate, a purification plate, an air outlet pipe, a gas sampling port, Coarse filter screen and activated carbon adsorption layer, a fan is arranged above the box, and the right end of the fan is provided with an exhaust gas inlet. An air guide plate is provided, a windmill is provided on the left side of the air guide pipe, a partition is provided in the box, a see-through board is provided on the right side of the partition, an activated carbon adsorption layer is provided above the see-through board, and an activated carbon adsorption layer is provided on the left side of the partition. Purification plate, the left side of the box body is provided with an air outlet pipe, and the air outlet pipe is provided with a gas sampling port. The present invention is provided with a pipe box on the right side of the device, and several air pipes are provided at the bottom of the pipe box to pass waste into the liquid surface. Next, the solid impurities in the exhaust gas are further removed, which solves the problems of too slow gas flow and low purification efficiency of the existing device.