The present invention provides a fluorination method for a non-aromatic hydroxy compound. The fluorination method comprises that a non-aromatic hydroxy compound contacts a compound represented by a formula I in an organic solvent in the presence of an alkali to generate the fluoride of the non-aromatic hydroxy compound, wherein at least one of the hydroxyl groups in the non-aromatic hydroxy compound is substituted with F. According to the present invention, the preparation method has advantages of cheap and easily-available raw materials, mild reaction condition, simple operation, low cost, easy promotion and efficient reaction, and can provide obvious stereoselectivity to polyols having different steric hindrance. The formula I is defined in the specification.