The axial compression member test was conducted to investigate the stability performance of these members, including nineteen Q420 L220×20 specimens which slenderness ratio(λ) ranged from 30～90. The test results showed that when slenderness is λ>45,flexural buckling was observed and when slenderness is λ≤45,local or flexural-torsion or torsion buckling was observed. The applicability of local buckling wide thickness ratio formula and flexural-torsional buckling conversion slenderness ratio formula was researched. By means of inverse calculation segment length method, the column curve of the large size equal angle was got. The comparison with common size angle and parameter analysis was made. Calculation method of bearing capacity of large size equal angle was given. Two ends eccentric compression column curve was also researched, and a suggestion formula of slenderness ratio correction coefficient was given.
