The invention discloses a formula of ultralow temperature glaze. The formula comprises 32-36 parts of calcined borax, 21-23 parts of potash feldspar, 8-15 parts of calcined talcum powder, 6-8 parts of quartz, 8-9 parts of Xinhui powder, 5-8 parts of calcined Xingzi kaoline, 4-7 parts of limestone, 3-8 parts of Suzhou soil, 0.5-1 part of titanium dioxide, 2-6 parts of Zuoyun soil and 5-15 parts of zinc oxide. The invention simultaneously discloses a preparation method of the ultralow temperature glaze. The preparation method comprises the following steps of material preparation, material mixing, wet grinding, glazing, drying and calcining. The ultralow temperature glaze prepared by the formula and the preparation method is used for retouching various porcelain blanks and porcelain bodies; a favorable intermediate layer can be formed after glazing; the ultralow temperature glaze can be favorably combined with the porcelain bodies and has excellent mechanical property, and the bending strength of porcelain is more than 30 percent; meanwhile, the porcelain glaze surface is smooth, is of a pale grey and transparent color and luster, has no defect on the surface and meets the market requirements.