The invention discloses a catalyst for selectively synthesizing 4-methyl-2,6-di-tert-butylphenol and application of the catalyst. The catalyst is prepared from a molecular sieve as a carrier modifiedby any one of ammonium phosphate, ammonium hydrogen phosphate and ammonium dihydrogen phosphate, and an active component A and an active component B carried by the carrier, wherein the molecular sieveis an Hbeta molecular sieve, H-mordenite, an HY molecular sieve, an USY (Ultra-Stable Y Zeolit) molecular sieve, an REY molecular sieve or a SAPO-5 (Silicoaluminophosphate) molecular sieve; the active component A is Co, Cu, Ni or Fe; the active component B is at least one of phosphotungstic acid, silicotungstic acid, phosphomolybdic acid, silicomolybdic acid and sodium tungstate; by the carrier,the carrying amount of the active component A is 2-5%, and the carrying amount of the active component B is 2-10%. The catalyst disclosed by the invention is applied to p-methylphenol and isobutene ortertiary butanol to produce 4-methyl-2,6-ditertiary butyl phenol, and has the advantages of low catalyst cost, high raw material conversion rate, good product selectivity, long catalyst service life,simple use process and the like.