The invention discloses an ultrathin crystal stone and a manufacturing method thereof, and the ultrathin crystal stone is prepared from the following components in percentage by weight: 20%-26.6% of cement, 21%-34% of fly ash, 20%-30% of water, 0.6%-1.5% of inorganic resin, 10%-20% of a high-molecular polymer, 0.15%-0.5% of metakaolin, 5%-10% of magnesium hydroxide, 0.1%-0.2% of inorganic fiber, 0.1%-0.3% of an alkali-resistant glass fiber mesh, 0.2%-0.8% of a water reducing agent, 0.1%-0.5% of a defoaming agent and 0.5%-1% of a rapid hardening agent. According to the ultrathin crystal stone and the manufacturing method thereof, the problems that a traditional material is large in dead weight, inconvenient to construct, poor in weather resistance and not environmentally friendly can be solved, and therefore the purposes of being vivid in effect, ultrathin, light in dead weight, soft, bendable, convenient to construct, large in hardness, resistant to impact, high in weather resistance, long in service life, environmentally friendly, good in water resistance and resistant to cracking are achieved.