The invention provides a porcelain insulator with high cold resistance which comprises 22-30 parts of semi-mountain clay, 15-25 parts of Changfeng mud, 12 to 22 parts of illite; 10-18 parts of bauxite, 10-18 parts of a molecular sieve, 10-18 parts of bentonite, 10-18 parts of zirconium oxide, 10-18 parts of calcium phosphate fiber, 3-15 parts of reinforced fiber, 3-15 parts of boric acid, 1-8 parts of a modified nano titanium dioxide-silica powder additive, 2-8 parts of sepiolite powder, 1-8 parts of a coupling agent, 1-8 parts of a surfactant and 1-8 parts of an anti-freezing agent. The porcelain insulator disclosed by the invention is compounded by adopting various functional raw materials, so that the cold resistance of the porcelain insulator is improved. The invention also provides apreparation method of the porcelain insulator with high cold resistance. The preparation method comprises the following steps: preparing the modified nano titanium dioxide-silica powder additive; mixing, ball-milling and modifying the raw materials in batches; sieving, removing iron, carrying out filter pressing, aging, forming a blank, and drying; glazing and firing; and carrying out glue bindingand maintenance. The porcelain insulator obtained by the method provided by the invention has the characteristics of high mechanical strength and excellent freeze-thaw resistance.