The invention provides a specific primer for detecting the T1369G polymorphic site (rs757110) genotype of the SUR1 gene by a PCR method, and the specific primer is used in the preparation of reagents for detecting the T1369G polymorphic site of the SUR1 gene by PCR amplification of biological samples The application in the invention, the SUR1 gene T1369G polymorphic site detection kit containing specific primers and the application of the detection kit to predict the effect of sulfonylurea drugs. Sulfonylurea drugs are selected from glibenclamide, glibenclamide, glibenclamide, glibenclamide, glimepiride, glibenclamide, glibenclamide, glibenclamide, glibenclamide , glipizide, gliclazide, glipizide, and gliquidone, preferably gliclazide or glimepiride.