The bending load performance of flange-plate connections in steel tubular structures was studied. By using experimental methods and related bolt strain measurement device, four specimens containing different types of flange-plate connections were four-point bended with loading instruments. The mechanic features of bolts and flange-plates were monitored. The yield loading capacity and ultimate loading capacity of the connections were found and compared with the results obtained in the FEM method. It has been proved that they are identical with each other. The experiment results have revealed that the prying forces in the tensile region of flange-plate connections do exist, and the prying action of connections with a stiffener is stronger than that of connections without a stiffener. The safety margin of the connections is approximately 1.2.