The invention discloses a method of purifying pure terephthalic acid (PTA) by means of white mud after treatment of textile alkali dissolution waste water and crude terephthalic acid after degradation of waste Dacron silk cloth. The method includes the steps of: 1) integration of material addition, slurry blending and pre-heating: adding industrial reclaimed water or fresh industrial water accounting for 75-80% of total weight of raw materials into a slurry blending kettle, starting stirring and successively adding raw materials as well as high temperature activated carbon, a descaling agent, and a composite finishing additive, and feeding high-temperature reclaimed vapor after pressure reduced crystallization or temperature reduced crystallization to dissolve the raw materials and heat the raw materials to 150-180 DEG C to prepare slurry; 2) starting a tubular heater to heat the raw materials, and performing high-temperature and high-pressure filtration, pressure reduced crystallization, cooling and dehydration; and 3) wastewater treatment: neutralizing wastewater by lime, flocculating and discoloring the wastewater by a water purifying agent, and filtering the wastewater to remove residues, so that the purified industrial water can be applied in the material addition and slurry blending step. The method accelerates dissolution and filtration and saves energy cost and changes production from intermittent type into continuous type, thus improving production efficiency. The method has beneficial to balance of production processes, and reduces man-hour cost.