Based on the existing modal theory, the paper explored the method of damage identification of bridge structure by using wavelet analysis technique. Therefore 1∶10 steel truss girder bridge scale structure was tested simulated damage test by removing the rods in the gusset plate bolted way, and made modal curvature calculation for the modal shape of structure. Using Bior3.9 wavelet function in Matlab software to program, the paper extracted the wavelet transform coefficient of curvature mode signal and determine the structure damage according to the order of damage index and wavelet singularity analysis method of bridge nodes.The results show that the method can better identify the location of damage nodes and provide a reference for the theory research and application of similar engineering.