By theoretical instability calculation and physical bearing test,a small load-bearing cylindrical truss with 180 mm height is designed,which consisting of six groups of vertical rods and three rings. The three rings with diameter of 56 mm are located at the top,the bottom and the middle of the truss respectively,and the middle ring is made of steel bars with a slightly smaller diameter than the upper and lower rings. The six groups of vertical rods are arranged uniformly along the circumference,and the two vertical rods in each group is located inside and outside of the rings respectively,and in the same shaft section of the columns truss. The butt joints of the rings are welded by TIG welding,while the joints between the rings and the vertical rods are welded by resistance spot welding. The maximum load bearing capacity of the truss is 17 800 N,and the ratio of the maximum load bearing capacity to the mass is 82 N/g.