A composite steel-concrete circular column with inner I-shaped steel is the main bearing structure in the frame structure of construction works. Assessment of the strength capacity of the column keeps a very important role in the design. However, there has not been a full investigation on the composite steel-concrete circular column with inner I-shaped steel so far. In this paper, a calculation process of this type of column has been performed. To illustrate the calculation process, a computational example has been carried out for assessing the bearing capacity of the composite column. Simultaneously, the effect of the variation of several material parameters on the strength capacity of the column is investigated. This result will help engineers choose the appropriate design in the composite steel-concrete column.