FGD (Flue-Gas Desulfurization) gypsum waste is a industrial waste of the process of reducing SOx discharged in the combustion chamber of a coal-fired power plant by a lime mixture or limestone powder. FGD waste has a high CaSO4.2H2O content, so it can be ultilized as a setting regulator for cement, as a raw material for manufacturing of gypsum board or wall mastic, etc. However, in Vietnam there are not many studies on the treatment of FGD waste to produce building materials as well as to solve the current urgent problems of environmental pollution and lack of storage yards. This paper presents research on thermal treatment procedure for FGD waste to make blended gypsum binder. The results show that FGD waste after being calcined at 160oC in 2 hours can be used as a gypsum plaster. When using 50- 60% FGD gypsum adhesive in combination with portland cement and Meta kaolin mineral additives, it is possible to make a blended gypsum binder with strength range 5.0-18.1 MPa, fast setting and water-resistant.