The variable regulation of maximum principle stress and deflection of glass panel in hidden curtain wall were analyzed by using uniform negative and positive wind pressure tests. The curve of maximum principle stress and deflection were compared in the two different wind pressure conditions. The glass panel used in specimen is monolithic toughened glass. The dimension of the glass panel is 1000mm×1000mm and its thickness is 6mm. The dimension of silicone structural sealant is 12mm×8mm. Test result indicated that the maximum principle stress and deflection of every test point increase linearly with the increasing of the uniform load from 0.5kPa to 2.0kPa; the curve of maximum principle stress and flexural performance of glass panel have obvious differences when the specimen was tested in negative and positive wind pressure. When the glass panel was tested in positive wind pressure, its load-carrying capability was better than it was tested in negative wind pressure. The flexural performance of glass panel was also in the same way.