Introduction  The roof structure of the main workshop of the gas turbine power plant is a long-span space grid structure, which has high safety requirements. In the design process, the selection of structural schemes, loads and other factors have a crucial impact on the safety and economy of the roof truss structure, so it is of great significance to study the selection and load optimization of the roof truss structure for power plant construction.

  Method  In this paper, based on a gas turbine power plant project, the roof truss structure of its main workshop was designed and compared with two roofing types of heavy concrete roofing and light steel roofing with the help of SAP2000 structural analysis and design software, so as to optimize the loads and reduce the amount of steel under the premise of ensuring safety.

  Result  By design comparison, the height and mass of the single truss structure of the light roofing are smaller, which is conducive to the transportation and construction of the whole truss, and the steel used in the light roofing truss structure is only 48.2% of the steel used in the heavy roofing.

  Conclusion  In areas like wind environment, the use of light steel roofing has the advantages of high construction feasibility and good economic benefits.