The steel structure stadium project includes three parts: the grandstand steel structure and the large span space frame canopy, with a steel volume of 14,000 tons.  The joints of the roof ring truss are connected by tube to tube intersecting welding. The number of rods is large, the section size is large, and the spatial hyperbolic positioning accuracy is high, and the construction is difficult.  Especially national oval project key construction technology of large-span saddle cable net structure, the roof line network is the first domestic use of independent research and development of high vanadium airtight, is one of the largest single global span two-way orthogonal saddle cable net structure, and steel weight of the roof system of only about a quarter of the traditional roofing, perfectly embodies the concept of energy saving and environmental protection