The invention relates to a composite 
geopolymer lightweight 
moisture-regulating material and a preparation method thereof, and belongs to the technical field of composite materials. The 
moisture-regulating material is prepared from the following components: 100 parts by 
mass of a cementitious material, 105-115 parts by 
mass of an activator, and a light aggregate having the amount accounting for 2-5 times the volume of 
metakaolin, wherein the cementitious material is composed of 70-90 parts by 
mass of 
metakaolin and 10-30 parts by mass of modified diatomite, and the light aggregate is 
polystyrene particles. The preparation method comprises the steps: firstly, stirring 
solid powder evenly, adding the liquid activator, fully stirring in a concrete stirrer, then adding the 
polystyrene particles, stirring evenly, pouring into a mould smeared with demoulding oil in advance, placing the mould on a horizontal table top, allowing to stand, curing at 
room temperature for 1 d, then demoulding totake out a plate-shaped finished product. The prepared 
moisture-regulating material has the characteristics of high efficiency 
moisture absorption and 
desorption, light weight, heat preservation and high strength, no 
pollution in the preparation process, low 
energy consumption, no needing of pressure forming and simple process.