This device is used to stabilize heavy metals in fly ash and meet the requirements of landfilling. The fly ash, chelating agent, and cement are mixed and stirred in a certain proportion, and the harmful heavy metals in the fly ash are solidified and stabilized through chemical action, and they are not easy to leaching. The device features modular design, centralized control, simple and convenient operation, stable operation, and reduces the occurrence of secondary pollution. Main equipment of the system: mixer, screw conveyor, fly ash weighing hopper, chelating agent weighing hopper, bulk machine, packer.