The invention discloses a purification method of sevoflurane. The method comprises steps as follows: a coarse sevoflurane product to be purified is added to a rectifying still of a rectifying column for rectifying purification, the reflux ratio is controlled to be (3-5):1 after reflux is stabilized, a front fraction is collected from the top end of the rectifying column, the reflux ratio is decreased to (1-3):1 when the rectifying column top temperature is 53-57 DEG C, a positive fraction is collected from the top end of the rectifying column, purified sevoflurane is obtained, and collection is stopped when the rectifying column top temperature is decreased to 50 DEG C; the rectifying column is filled with stainless steel theta ring packing or stainless steel theta ring packing embedded with silica gel, and a silica gel column is connected below the rectifying column filled with the stainless steel theta ring packing in series. Silica gel is introduced, the adsorption of silica gel to hexafluoroisopropanol impurities is utilized, the distil-off time of hexafluoroisopropanol can be well delayed, and sevoflurane is effectively separated from common impurities and stubborn hexafluoroisopropanol impurities through control on the temperature of the rectifying still and the reflux ratio.