The invention discloses anti-crack modified quartz-based mica powder full mold paint. The anti-crack modified quartz-based mica powder full mold paint is prepared from, by weight, 100-102 parts of quartz powder, 0.9-1.1 parts of modified starch, 0.9-1.1 parts of carboxymethylcellulose, 2.4-2.6 parts of sodium bentonite, 0.9-1 part of mica powder, 0.8-0.9 part of tetrapod-like zinc oxide whiskers, 0.9-1.1 parts of silica sol, 10-13 parts of ethanol, a proper amount of water, 0.4-0.5 part of nano spherical aluminum oxide, 0.7-0.8 part of straw powder and 4-5 parts of sodium hydroxide solution with the concentration being 20-25w%. According to the anti-crack modified quartz-based mica powder full mold paint, the nano spherical aluminum oxide and the straw powder are used, and the straw powder is modified, so that the crack resistance of the paint is improved; in addition, the nano spherical aluminum oxide is used for modification, so that the heat resistance of the straw powder is improved, and the situation that sudden carbonization occurs during casting, a large amount of gas is released, and consequentially air holes of a casting are caused is avoided; and furthermore, the strength and smooth finish of the paint after sintering are improved, and the spalling resistance is improved.