The present invention relates to the application of expanded vitrified microspheres in sand-in-water base paint, sand-in-water base paint, preparation method and sand-in-water paint. The sand-in-water base paint is prepared from the following components by weight: 20-30 parts of ionized water, 0.2-0.3 parts of dispersant, 0.2-0.5 parts of defoamer, 1.0-2.0 parts of antifreeze, 1.0-2.0 parts of coalescence aid, 1-5 parts of expanded vitrified microbeads, titanium dioxide 1-5 parts, 1-8 parts of kaolin, 0.8-2.0 parts of cellulose, 1.0-2.0 parts of pH regulator, 20-40 parts of emulsion, 0.1-0.5 parts of preservative, 5-10 parts of 10wt% protective colloid solution, 0.1-0.5 parts of thickener and 40-50 parts of quartz sand; add expansion vitrified microbeads in the sand-in-water base paint, reduce the proportion of particles in the sand-in-water base paint, improve the suspension of particles in the base paint, and make The suspension of particles in the sand-in-water coating prepared by it is improved, which makes the size of the sand-in-water particles more uniform during the shear granulation process, improves the coverage of the finished sand-in-water coating, and reduces the spraying consumption of the sand-in-water coating. quantity.