With the increasing number of long-span continuous beam-arch composite bridges in China, the construction quality of steel pipe arch has an important influence on the structure of bridge completion stage and operation stage. It is necessary to study the mechanical behavior of steel pipe arch in the construction process. In this paper, ABAQUS finite element analysis software is used to create different construction stages of steel pipe arch, and analyze the mechanical characteristics such as stress and deformation of steel pipe arch in each construction stage. The calculation results show that the stress state at the foot of the steel pipe arch should be paid attention to in the construction stage of the steel pipe arch. After the completion of the steel pipe arch assembly, the arch top and the arch bottom at the bracket position bear tensile stress and compressive stress respectively. After the steel pipe arch support is removed, the entire steel pipe arch is under compression and the compression degree at the bottom of the arch is greater than that at the top of the arch under the action of the cable force value of 1 074.4 kN. During the overall longitudinal movement of the steel pipe arch, the stress of the steel pipe arch changes between -12.49 MPa and 11.10 MPa. Due to the effect of the temporary cable at the arch foot, there is the maximum compressive stress at this position. In the construction stage of the completed bridge, the compression degree of the vault of the steel pipe arch decreases from the arch center to both sides, and the compression degree of the arch bottom decreases from the arch foot to the arch center. Through the finite software analysis and calculation, the stress and linear of the steel pipe arch meet the requirements of the specification.