The invention relates to a chemical complete synthesis method for three novel PTP1B inhibitors and application of the PTP1B inhibitors in medicines for treating type II diabetes. The chemical structural formulas of the PTP1B inhibitors are shown as follows: a compound 6 (4, 5-di-(2, 3-dibromo-4, 5-dimethoxybenzyl)-1, 2-dimethoxyphenyl): groups connected with C of 2', 3', 2'' and 3'' sites of a benzene ring are bromine atoms, and C of 1, 2, 4', 5', 4'' and 5' sites is connected with methoxyl; a compound 7 (3-bromo-4, 5-di-(2, 3-dibromo-4, 5-dimethoxybenzyl)-1): the groups connected with C of 3, 2', 3', 2'' and 3'' sites of the benzene ring are bromine atoms, and C of 1, 2, 4', 5', 4'' and 5' sites is connected with the methoxyl; and a compound 8 (3-bromo-4, 5-di-(2, 3-dibromo-4, 5-dyhydroxylbenzyl)-1, 2-dihydroxybenzene): the groups connected with C of 3, 2', 3', 2'' and 3'' sites of the benzene ring are bromine atoms, and C of 1, 2, 4', 5', 4'' and 5'' is connected with hydroxyl. The three compounds enhance the sensitivity of an insulin receptor through inhibiting the activity of protein tyrosine phosphatase 1B and have good therapeutic action on insulin resistant type II diabetes.