To address the uncertainty of structural states during construction and the scarcity of field monitoring data, which make it difficult to fully characterize structural pose and force conditions, we developed a state identification method based on limited monitoring information. For the reference state, the key control parameters governing the equilibrium of the initial configuration were identified. For the construction process states, pose-correction parameters and key state parameters were jointly identified from a small number of observations. State identification was implemented by integrating finite element analysis with a global–local optimization strategy. The vertical rotation construction of the main arch of an overpass bridge was investigated as an engineering case. The results show that the method can accurately recover the prescribed cable force configuration in the pre-construction reference state and stably identify spatial pose changes and cable force redistribution at several discrete construction states. The error indices remained generally small, and the results at the constraint points agreed well with those at the validation points. The proposed method provides an effective technical approach for state assessment, geometric control, and parameter updating during the construction of complex bridges.