The invention discloses a purification method of
chlorine trifluoride, and belongs to the field of
fine chemical engineering. The purification method comprises the following steps: introducing
chlorine trifluoride crude products into a
tower kettle of a rectifying
tower; performing vacuum-pumping on the rectifying
system, starting to heat the
tower kettle after the vacuum degree is stable, and performing total refluxing for 3-15 h to enable the
impurity composition of which the
boiling point is lower than that of
chlorine trifluoride to be gathered at the top of the rectifying tower; when the temperature of the tower kettle is at a temperature of 0-5 DEG C, the temperature of the rectifying tower top is 2-3 DEG C below zero, then collecting front
cut fraction at a
reflux ratio of 30-300 and condensing and recovering; when the temperature of the tower kettle is 5-8 DEG C, the temperature of the rectifying tower top is 3-6 DEG C, collecting medium fraction at a
reflux ratio of 10-90, and condensing and recovering; when the temperature of the tower kettle increases for 2 DEG C, that is, the temperature is 7-10 DEG C, the temperature of the rectifying tower top is 5-8 DEG C, collecting after
cut fraction at a
reflux ratio of 15-140, and condensing and recovering; when the temperature of the tower kettle is higher than or equal to 15 DEG C, stopping collecting after
cut fraction, stopping heating, stopping vacuum-pumping, and finishing rectifying, wherein the medium fraction is the
chlorine trifluoride refined product. The method is simple to operate and is high in purification efficiency.