Abstract: Lime and slag could be used to prepare lime-slag/soil composites. The effect of lime content, slag content and moisture content on heat & moisture comprehensive property of lime-slag/soil composites was studied by response surface methodology and the preparation technology for lime-slag/soil composites was optimized. The results show that heat & moisture comprehensive property is influenced by lime content, slag content and moisture content. Optimal program is obtained by regression analysis that lime content (mass ratio between lime and compo-site) is 10.19%, slag content (mass ratio between slag and composite) is 4.02%, and moisture content (mass ratio between water and composite) is 9.00%. Average equilibrium moisture content of optimal lime-slag/soil composites is 12.725%, thermal conductivity is 0.798 W/(m·K), optimal lime-slag/soil composites have favorable heat & moisture comprehensive property. Under the effect of alkaline excitation and micro aggregate, optimal lime-slag/soil composites have the whole and compact construction through structural analysis, and reasonable mechanical performance and heat & moisture comprehensive property.