Abstract: The relationship betweeu wood-gypsum ratio and water gypsum ratio was studied. The effects of temperature on hydration process, the hydration system and the morphology of gypsum were explored by analyzing the concentration of Ca2+in tire hydrating system and the morphology of gypsum crystals. In addition, the physical and mechanical properties of the gypsum sawdust board were analyzed. The results showed that these ratios satisfied the formula,to=0. 54x+0.28. each water-gypsum ratio has a corresponding wood-gypsum ratio to fit. The water-gypsum ratio and the corresponding wood-gypsum ratio wouht make the board’s properties best together. These ratios satisfied when the temperature was 40℃, the gypsum hydration time shortened and the board had high strength. The application of this condition shortened the production petted and improved the effieieney.