Abstract: To explore the solution to the problems of water shortage and multi-solid waste treatment in the western coal mining area, the desulfurization gypsum, fly ash and cement in Ningdong mining area were selected as the main raw materials. The micro-morphology of the raw materials and the composition after less water ratio were analyzed. The initial fluidity and the strength of 7 d and 28 d after demoulding were used as indicators to optimize the ratio. The scheme of 3 factors 3 levels and 17 combinations was designed. A response surface regression model was established to analyze the effects of single factor and multi-factor interaction on the strength and fluidity of low-water filling materials. The results show that the mass ratio of fly ash to cement is an important factor affecting the strength. The mass fraction of slurry is an important factor affecting the fluidity. The optimal mix ratio is desulfurization gypsum mass fraction 53%, fly ash and cement mass ratio 2∶1, slurry mass fraction 74%. The relationship between wave velocity and strength shows that the wave velocity of the filling body could be used to predict the strength.