As a new energy transfer medium, supercritical CO₂ (S-CO₂) has shown broad application prospects in the field of energy. However, supercritical CO₂ can induce high temperature corrosion of structural metallic materials as high-temperature oxidation and carburization. The synergistic effect of corrosion and stress can aggravate the corrosion of metallic materials and deteriorate their mechanical property, accelerate their degradation, and even induce environmental cracking, all of which result in serious consequences. Therefore, this article elucidates the supercritical CO₂-induced oxidation and carburization, and their coupled effect; summarizes the methods to evaluate the environmental cracking induced by synergistic effect of corrosion and stress in high-temperature high-pressure supercritical CO₂ environments; analyzes metallic material performances under the synergistic effect of corrosion and stress, including the change of mechanical property after corrosion, stress corrosion cracking, creep, corrosion fatigue, thermal cycling and effect of surface residual stress on corrosion, etc.; and sums up the behavior and mechanisms of environmental cracking of metallic materials. It is intended to provide theoretical guidance and technical support for the material selection and environmental cracking prevention in supercritical CO₂ systems.