Abstract: This paper focuses on the reliability of prefabricated structural elements for the Nanjing Weisan Road river-crossing tunnel, which is a double-deck large-diameter tunnel, during the construction stage. Midas/Civil software is used to carry out a numerical simulation for studying the loads appled by the frame girder machine when it erects prefabricated elements and to analyze the load bearing capacity of structural elements under different loading conditions during construction. Additionally, a 1∶1 model test is carried out for verifying and evaluating the safety of recommended construction loads. The results show that the deflection correction coefficients and strain correction coefficients of the carriageway deck and longitudinal beam are both between 0.7~1.0 but less than 1.05; the integral rigidity and bearing capacity of the structure, which is in the elastic deformation state, meets the design requirements and has less structural residual deformation and strain; and no obvious defects are found in the carriageway deck, brackets, columns and the test sections involved in the load testing site.