Fly ash from waste incineration is rich in heavy metals, dioxins and other pollutants, which is a hazardous waste and needs to be treated in an environmentally sound manner. At present, the solidification/stabilization + landfill method is widely used in domestic waste incineration plants to dispose of fly ash. In this paper, we sampled the domestic grate furnace waste fly ash and fluidized bed fly ash, and their chelated products. We compared and analyzed the characteristics of two types of fly ash, the leaching characteristics of heavy metals before and after chelation, and analyzed the effects of the differences between fly ash before and after chelation on the stabilization of heavy metals using XRD, XRF, and SEM methods. It was found that chelation can bring the heavy metal problem of fluidized bed fly ash under control and the leaching concentrations of Cd in the fly ash of grate furnace after chelation were still exceeded, pointing out the shortcomings of the current solidification/stabilization method for fly ash treatment. This method can make the fly ash surface dense by cement wrapping, which can reduce the leaching of heavy metals to a certain extent, but the effect of stabilizing heavy metals with chemicals was not obvious. Therefore it was not easy to achieve long-term stabilization of heavy metals and had no sustainable development potential. This paper can provide a reference for further research on new waste incineration fly ash disposal technologies in a targeted manner.