Focusing on a highway continuous steel plate composite girder bridge, the mechanical properties of its construction process and bridge state were tested and monitored, and the mechanical properties of steel plate composite girder were studied, providing technical support for the design optimization of similar steel plate composite girder bridge. The results show that the measured stress and deflection are in agreement with the theoretical values.The structural stress in the construction process meets the requirements of the code; The test bridge is in elastic working stage during static test.