The invention relates to a process for synthesizing 2,3,6-trimethylphenol by phenol, and belongs to the technical field of medicine chemical industry. The process comprises the following steps of: firstly, carrying out a gas-phase reaction by mixing the phenol with methyl alcohol through a catalyst to obtain 2,6-dimethylphenol; and preparing a 2,3,6-trimethylphenol finished product by carrying out a sulfonation reaction, an esterification reaction, a friedel-crafts acylation reaction and a desulfonation reaction. According to the process for synthesizing the 2,3,6-trimethylphenol by the phenol, the problems that the existing m-cresol raw material is lack so as to seriously restrict the yield of the 2,3,6-trimethylphenol, and the service life of a catalyst is largely reduced and the production cost is increased because a catalytic reaction needs to be carried out at high temperature under high pressure during meta-methylation are solved. According to the process for synthesizing the 2,3,6-trimethylphenol by the phenol, the transformation rate and the selectivity of a reaction are improved; and meanwhile, the preparation cost of products is largely reduced, and the economical benefits and the social benefits are excellent.