Due to the problem that local bucking is easy to occur on steel tube of concrete-filled skin steel tube (CFST) columns, the applications and researches of a new type composite column, CFST with stiffening ribs, have been reported in recent years, and the problem of CFST is expected to be solved through the change of structural form. In this paper, the effects of different types of stiffening ribs on mechanical properties of concrete-filled double skin steel tube (CFDST) columns were studied. Three types of stiffeners including single rib, triangle rib, and square rib were designed to strength CFDST columns, and three slenderness ratios of 4.0, 5.0 and 6.0 were applied for each section type of CFDST columns. The axial compression tests of CFDST columns were conducted, and full-filled strain of specimens were monitored and analyzed. Besides, the influences of different stiffener types on the ultimate bearing capacity, ductility, local bucking and load-displacement curve were investigated and analyzed. It was found that local bucking of CFDST columns with different slenderness ratios are most likely to occur from 1/8 of height to end face or from 1/8 to 3/8 of height. Compared with no-stiffener CFDST columns, the ductility of CFDST columns with stiffeners has improved greatly, and the specimens with triangle ribs show a 76% increase on average in ductility. However, the ultimate bearing capacity has different decrease. A modified formula is built and the calculated values are matched with test results well.
