A pure terephthalic acid device refining mother liquor recycling system of the invention consists of a filter, a control valve and a control unit. The technique of the invention mainly includes that mother liquor is filled in the filter in advance at the beginning of the filtering to result in a filtering assisting layer formed on the inner surface of a filter core. A filter cake which is formed from solid particles is dried, immersed in acid and separated. The solid particles enter a beating tank for secondary beating and return an oxidation unit for the oxidation. Filter liquid directly enters PTA refining unit to be reused as process water. The system and the method of the invention reach to various expected goals through tests and the energy and water saving effect is obvious. The recycling rate of organic particles in the refining mother liquor reaches to 98 percent. And the PX conversion rate and the product yield rate are ensured to be improved effectively. The COD value of therefining liquor lowers from 5000ppm to 2400ppm. The conversion rate and the water detachment consumption are lowered.