Abstract: The spatial steel pipe truss and radiation beam horizontal supporting structures with the same diameter of 30 m were selected for comparison，the two models were applied with 0，800，1 600，2 400 kN loads and analyzed by the ANSYS software under different loads． The results showed that the displacement of the two finite models as the load increased． Under the same load，vertical displacement of the radiation beam support system and the spatial steel truss was not so far different． With the rod force in the elastic range，the maximum vertical displacement of two structure systems displayed a significant linear relationship as the load changed． Hence，the steel truss support system had a higher ability to withstand the load than the radiation beam support system．