The first degree second order moment method (JC method) recommended in Unified Standard for Reliability Design of Building Structures (GB500682001) was applied to analyze the reliability of steelreinforced highstrength concrete filled steel tubular slender columns. Several performances were studies, which were the influences of different load combinations, specific values of loads, strength grades of concrete, thickness of steel tube, area of crosssection of structural steel, steel yield strength and slenderness ratio on the reliability of the composite column. It was found that, when the slenderness ratios were within common range, the reliability indexes of the proposed formulae satisfied the demand of GB500682001 for plastic material on the whole. And it was concluded that the reliability index varied with the load combination and specific value of loads. The reliability index increased with the increase of concrete strength grade and decreased with the increase of steel tube thickness. Furthermore, steel yield strength and slenderness ratio had different influences on the reliability indexes.