Abstract: Fly ash from municipal solid waste incineration is a kind of hazardous solid waste. It must be cured and stabilized to meet the "Standard for Pollution Control of Domestic Waste Landfills" before it can be landfilled. Goethite is a kind of solid surfactant with abundant hydroxyl functional groups on its surface, which can be used to solidify waste incineration fly ash by complexing metal ions with hydroxyl groups on its surface. In this paper, the influence of technological parameters on toxic leaching effect of goethite cured fly ash was discussed, and the hydroxylation characteristics of goethite surface were characterized by acid-base titration, and the density of hydroxyl active sites on goethite surface was calculated by processing acid-base titration data with Gran diagram. The results show that under the conditions of 15% goethite, 0.4 liquid-solid ratio and 3 days solidification time, the cured fly ash can meet the entry requirements of domestic refuse landfill; metal ions can enter stern layer on goethite surface and be adsorbed tightly, while alkaline conditions are more conducive ion to adsorb on diffusion layer on goethite double layer.