Through semidry process, the wood fiber as reinforced materials and the industrial flue gas desulfurization waste calcinated calcium sulfate hemihydrate as an inorganic adhesive produced the environmental gypsum fiber board. This process is effective on utilization of desulfurization gypsum, which reduced the pollution of the environment and the demand of the natural gypsum, further to protect the natural environment. As green building decoration materials, gypsum fiber board has good prospects for development. The research results show that it is remarkable that the amount of the composite retarder is effective on the static bending strength, internal bond strength, grip screws to impact; the ratio of the wood and plaster is effective on the absorbent thickness expansion rate.