The invention discloses a preparation method of 2,6-dihydroxytoluene. The preparation method comprises the following steps of dissolving prepared 3,5-diamino-4-methylbenzoic acid in water, adding dilute sulphuric acid, stirring uniformly, adding ZnCl2, reducing the temperature to minus -2 to 2 DEG C after stirring uniformly, dropwise adding a
sodium nitrite solution into the mixture, continuouslystirring to react for 5-6 hours after the dropwise adding is finished, then adding water and dilute sulphuric acid, mixing uniformly, then heating for boiling, reacting for 30-45 minutes, then addingsodium
hydroxide, carrying out
reflux reaction for 1-2 hours, cooling to
room temperature, adding
diethyl ether, stirring for 20-40 minutes, then adding
zeolite, stirring and mixing for 1-2 hours, carrying out reduced-pressure
distillation after filtering, and preparing the 2,6-dihydroxytoluene. The preparation method disclosed by the invention has the beneficial effects that the raw-material costis low, the operation is simple, safe and reliable, the requirements for the environmental conditions are mild, the product purity is high and the yield is high.