The invention discloses a clay-based thermal phase transition multifunctional sand fixing material, and belongs to the technical field of sand preventing and sand fixing. The material is prepared by a method which comprises the following steps: crushing biomass waste into crushed slag; mixing a biomass degradable raw material and the biomass waste slag in a certain proportion at a high speed; then, performing vacuum immersion treatment to obtain a thermal phase transition energy storage additive; finally, uniformly mixing the thermal phase transition energy storage additive and clay in a certain proportion, paving and spreading the mixture on the surface of a moving dune, and spraying water on the mixture to enable the water to penetrate into the surface and crusts. A heat energy storage phase transition material and a water retaining material which are relatively low in cost are introduced by adding a chemical sand fixing idea on the basis of a clay-based sand fixing material; the prepared energy storage thermal phase transition multifunctional clay-based sand fixing material has the advantages of physical sand fixing, chemical sand fixing and plant sand fixing; the sand fixing effect is good; the cost is low; meanwhile, the problems in pure physical sand fixing and chemical sand fixing are solved, and the difficult points of the plant sand fixing is also solved, so that the clay sand fixing can be popularized and applied more comprehensively.