Because of the characteristics of an ultra-long isolated structure in cold regions， such as long construction period， complex plane shape， large structure span， significant seasonal temperature difference， and multi-stage construction， a calculation method for the thermal shrinkage deformation of the isolation layer during the whole construction process of the ultra-long isolated structure is established. Combined with the site construction progress， scheme， and sequence， the construction process is simulated in detail using finite element software， and the size and evolution law of the thermal shrinkage deformation of the isolation layer during the construction process of the structure are analyzed. The simulated results are compared with the field measurement results. Finally， the influence rules of structure construction in stages， construction path， and post-pouring belt setting mode on the thermal shrinkage deformation of the isolation layer are discussed. The analysis results show that the simulation results of the thermal shrinkage deformation during the construction process agree well with the measured results. The thermal shrinkage deformation of the isolation layer generally changes periodically with the progress of construction and has the change in ambient temperature. When the ultravery-long isolation structure is constructed in multi-stage， there is mutual restraint between the structures in each stage， and the final thermal shrinkage deformation of the structure is due to the coordinated deformation of the structure in each stage. Reasonable construction path and structural unit division can effectively reduce the thermal shrinkage deformation of the isolation layer. Compared with the case without the post-pouring belt， the maximum thermal shrinkage deformation of the isolation layer only decreased by 6.3% when the reinforcement was connected at the post-pouring belt， while the maximum thermal shrinkage deformation of the isolation layer decreased by 36.3% when the steel reinforcements were fully overlapped at the post-pouring belt.