Abstract: The load-bearing frame of the combined loading test device consists of four parts,such as load-bearing column,loading head,connecting rod and retaining nut. The load-bearing column occupies about 40% of the weight of the whole load-bearing frame. On the basis of changing the wall thickness of the circular tube section of the load-bearing column,Abaqus 6. 14 is used for calculation and analysis of the load-bearing frame,and the lightweight design is finished. At the same time,engineering algorithms is used to check the stability of the load-bearing column. The results show that when the wall thickness of the load-bearing column is 24 mm,the static strength and stability of the entire load-bearing frame meet the usage requirements,and the load-bearing column reduces the weight by about 30%.