The desulfurization ash, fly ash and metakaolin were uesd to prepare the geopolymer. Compressive strength test demonstrated that the optimum mass ratio of desulfurization ash, fly ash and metakaolin was 30:55:10 and the max strength reached 17.3 MPa. The XRD and SEM show that there is not new crystalline phase. The main crystalline phase of the matrix is non-reacted mullite in the fly ash. It was suggested that the emission of CO2 and SO2 were rehabited from geopolymer by analysis of those compositions volatilizing using TG/MS.