Abstract:Based on the Box-Behnken response surface method, a three-factor, three-level test was designed using Design-Expert 8.0.6 software with 5%~15% ceramic powder, 10%~20% ordinary silicate cement and 5%- 15% quicklime as the factors considered to investigate the effects of each factor on the compressive strength and softening of gypsum-based composite cementitious materials at 7 d and 28 d ages coefficients at 7 d and 28 d. The effect of each factor on compressive strength and softening coefficient was analyzed by quadratic regression fitted model ANOVA to determine the magnitude of the influence of each factor on admixture and the optimal mix ratio. The results showed that the effects of ceramic powder and cement admixture on 7 d and 28 d compressive strength were highly significant, followed by quicklime; the admixture of ceramic powder on softening coefficient was significant, followed by quicklime, and cement was the most inferior. The optimal ratio is 10.88% of ceramic powder, 15.51% of cement and 10.65% of quicklime, with a prediction error of no more than 10% verified by the test. The research results provide a test basis for further optimization of the constructability, selfwarming and durability of gypsum-based composite cementitious materials.