In order to suppress the buckling deformation and enhance bearing capacity of cold-formed steel columns, a systematic study was conducted using a combination of experimental testing, numerical simulation, and theoretical analysis on cold-formed steel-geopolymer foam concrete composite columns. The load-axial displacement curves, test process and failure characteristics of the members were analyzed. The failure modes and bearing capacity results of different types of members were compared and the effects of different factors on the axial compression performance of the members were discussed. The results show that: the ultimate bearing capacity of the composite column is 1.4 times higher than that of the CFS built-up column. When the width-thickness ratio is in the range of 60-100, the utilization rate of geopolymer foam concrete is higher. For every increase in the density of foam concrete, the ultimate load of the composite column increases by about 1.5%. From the perspective of steel consumption, the setting of symmetrical single ribs has a more significant impact on enhancing the ultimate bearing capacity of composite columns. Based on the experiment and numerical simulation, the ultimate bearing capacity of composite columns is calculated according to the calculation methods in existing relevant codes. It is found that the calculation method given by the ′Code for design of composite structures′ can roughly estimate the ultimate bearing capacity of the composite columns. Finally, a calculation method suitable for the axial compression bearing capacity of the composite columns is proposed, and the accuracy of the formula is verified.