Abstract: Geometry and stiffness of assembled flexible structure are different because of changes in tensioning process and construction sequence. Seeking rational applying sequence is the key to the construction technology. Using the finite element simulation method，and combining with the Nanjing expo center project it was studied the construction sequence of large-span beam string structures. As example，three typical construction sequences' variation tendency of cable force and displacement was analyzed，and then their curves were given. In the end, according to the structure forming state by different construction sequence，some recommendations for selecting construction method are made.