The invention discloses a gastrodin chemical synthesis method. The method comprises the steps as follows: under Lewis acid catalysis, D-glucose reacts with acetic oxide, pentacetyl-D-glucose is obtained and not subjected to separation and purification; the pentacetyl-D-glucose and the p-cresol are catalyzed by Lewis acid and subjected to a glycosylation reaction directly in an organic solvent, so that 4-methylphenyl 2,3,4,6-O-tetracetyl-b-D-glucopyranoside is generated; then the 4-methylphenyl-2,3,4,6-O-tetracetyl-b-D-glucopyranoside reacts with 1,3-dibromo-5,5-dimethylhydantoin under the action of an initiator or in solar radiation, so that 4-bromomethyl-2,3,4,6-0-tetracetyl-b-D-glucopyranoside is obtained; then under the alkalescence condition, 4-bromomethyl-2,3,4,6-0-tetracetyl-b-D-glucopyranoside is hydrolyzed selectively, so that 4- Hydroxymethyl phenyl-2,3,4,6-O-tetracetyl-b-D-glucopyranoside is obtained; and finally an acetyl protecting group is removed from a methyl alcohol-sodium methoxide system, so that the gastrodin is obtained. Compared with a conventional method, the gastrodin chemical synthesis method has the advantages as follows: raw materials are easy to obtain, the cost is low, reaction products in all steps can be prepared through recrystallization, the process is simple, the reaction period is short, the yield is high, and the method is more suitable for preparing the gastrodin in large scale.