Concrete-filled steel tubular (CFST) structures in service are usually subjected to a combination of loads and corrosion, and they need to be strengthened for continued use. Carbon fiber reinforced polymer (CFRP) is characterized by high strength, corrosion resistance, and convenient construction. Experimental and numerical investigations are conducted to study the axial compressive behavior of CFRP-strengthened circular concrete-filled steel tubular stubs considering preloading and corrosion (C-CFRP-PCCFST). Four C-CFRP-PCCFST specimens and one un-strengthened specimen are tested under axial compressive load. Finite element (FE) models of the C-CFRP-PCCFST stubs are established and validated by experimental results. Then, a parametric study on the yield strength of C-CFRP-PCCFST stubs is mainly carried out in terms of different corrosion parameters, material properties, and preloading conditions. The results show that the preloading has a negative effect on the yield strength of C-CFRP-PCCFST stub columns, while its effect on the ultimate strength can be neglected. The yield strength of C-CFRP-PCCFST stub columns decreases with the increase of corrosion parameters. The effects of corrosion and preloading on the yield strength of C-CFRP-PCCFST stubs are reflected by introducing strength reduction factors Re1 and Re2, respectively. Based on the results of the parametric study, the equation for predicting the yield strength of C-CFRP-PCCFST stubs is proposed.