The invention relates to 
diatom sand beads and high-strength, environment-friendly and thermal-insulation 
mortar containing the same. The 
diatom sand beads are prepared from second-class and third-class diatomite used as a 
raw material through four steps including 
drying, purification, 
granulation and 
roasting. The 
diatom sand beads are light in weight, environment-friendly and high in adsorbability and have the advantages of damp prevention, 
fire prevention, purification, 
thermal insulation and the like. The thermal-insulation 
mortar is prepared from 50%-60% of the diatom sand beads, 10%-20% of diatom 
powder, 5%-8% of environment-friendly latex 
powder, 10%-20% of 
cement, 1% of wood 
fiber, 2% of 
cellulose, 0-10% of glass beads and water. The thermal-insulation 
mortar can replace 
cement mortar to be directly applied to building wall 
brick surfaces, when the thermal-insulation mortar is used for an exterior wall, other decoration processes can be performed directly on the thermal-insulation mortar, and when the thermal-insulation mortar is used for an interior wall, the thermal-insulation mortar can well adsorb indoor 
formaldehyde produced during decoration, is environment-friendly and can purify 
indoor air; the thermal-insulation mortar has the advantages of being light in weight, low in heat 
conductivity coefficient, environment-friendly, thermal-insulation, high-temperature-resistant, fireproof, low-temperature-resistant, 
noise-reducing, damp-proof, 
mildew-proof, anti-condensation, free of radioactive substances, stable in physical and 
chemical property and the like.