Abstract: Lithium fluoride（LiF）is an important inorganic fluoride with wide uses in many fields.Synthesis of high purity LiF included direct synthesis method，ion exchange method,and solvent extraction method.Direct synthesis method also included dry method and moisture method.Processes of various methods were introduced in detail.Compared to the moisture method，dry method has many advantages,such as simple process，lower investment，and suitable to continuous production.By using solvent extraction method，the mass fraction of transition metals in LiF product can be reduced to 10^-9 degree，and it is especially suitable to manufacture optical fiber and electrolyte of rechargeable lithium ion battery.

Key words: lithium fluoride, direct synthesis method, ion exchange method, solvent extraction method