NOVELTY - Recovering tert-butyl catechol residue involves first pressure-reducing, rectifying/purifying from byproduct 3,5-di-tert-butyl catechol(d1-TBC residual liquid in para-tertbutylcatechol), then recovering 3,5-di-tertbutyl catechol and catechol, catalyst HL-8 same as reverse alkylation reaction para-tert-butylcatechol, reaction liquid, or directly para-tertbutylcatechol residual liquid and catechol, catalyst HL-8 are carrying out reverse alkylation reaction para-tertbutylcatechol, reaction liquid, reaction liquid para-tert-butylcatechol by decompressing/rectifying.    USE - For recovering tert-butyl catechol residue (claimed).    ADVANTAGE - The method reduces production costs, recycling of resources, and improves the market competitiveness of products.    DETAILED DESCRIPTION - Recovering tert-butyl catechol residue involves a first pressure-reducing, rectifying and purifying from a byproduct 3,5-di-tert-butyl catechol(d1-TBC residual liquid in the para-tertbutylcatechol), then 3,5-di-tertbutyl catechol and catechol, catalyst HL-8 the same as a reverse alkylation reaction para-tert-butylcatechol, reaction liquid, or directly para-tertbutylcatechol residual liquid and catechol, catalyst HL-8 are carrying out reverse alkylation reaction para-tertbutylcatechol, reaction liquid, reaction liquid para-tert-butylcatechol by decompressing and rectifying to obtain the weight percentage content is not less than 99% of para-tertbutylcatechol, involves 1) adding proper amount of to the flask with efficient rectification column para-tert-butylcatechol residual liquid, charging nitrogen into the flask, raising the temperature, and then the negative pressure by a vacuum pump, a vacuum is 175-187 degrees C at 4-40 mm Hg, in the flask temperature is controlled at 170-200 degrees C, a reflux for half an hour, controlling the reflux ratio is 1: 1 to 5:1, a distillate, collecting fraction to obtain the weight percentage content is 3%, 5-di-tert-butyl-butylcatechol 98%, 2) of catechol pyrocatechol, 3,5-di-tert-butyl catechol and catalyst HL-8 is added with stirring, a thermometer, an air condenser pipe according to the proportion in flask, nitrogen removing air, starting to stir, and slowly raising the temperature, where the reaction temperature is kept at 140-155 degrees C, preserving temperature and reacting for 6 hours, after finishing reaction, obtaining the weight percentage content is more than 64% of para-tertbutylcatechol reaction solution, where the catalyst HL-8 is the concentrated sulfuric acid and the compound of methanesulfonic acid, concentrated sulfuric acid and is 1 the mass ratio of the methyl, 10 parts of catalyst, HL-8 is 0.1 of 3, 5-di-tert-butyl-1-butylcatechol, pyrocatechol and 3, 5-ditert-butyl pyrocatechol mol ratio is 1:0.5 to 0.8, 3) adding high-effect rectifying column of a para-tertbutylcatechol reaction solution, the lower the temperature of the kettle is 160-190 degrees C, vacuum 10-40 mm Hg, decompressing and rectifying to obtain more than 99 wt.% of para-tert-butylcatechol, para-tert-butylcatechol rectification yield is 90-95%.