To address the challenges of hydraulic fracturing in unconventional oil and gas reservoirs in terms of water resource consumption，formation damage of water sensitivity，and environmental pollution，this study systematically investigates the fracturing mechanism，application status，and engineering challenges of the supercritical carbon dioxide （SC-CO₂） fracturing technology. Compared with water-based fracturing fluids，SC-CO₂ is more likely to generate complex fracture networks because of its low viscosity，high diffusivity and near-zero interfacial tension. The mechanism of “modification-permeability enhancement” is clarified：SC-CO₂ reconstructs pore-fracture systems through mineral dissolution and organic matter extraction，while also degrading rock strength and increasing brittleness，which jointly facilitates fracture initiation and propagation. Recent advances in fluorine-/silicon-based thickeners，non-fluorinated thickening systems，and SC-CO₂ jet and compound fracturing technologies are summarized. Although challenges remain in proppant transport，equipment compatibility，cost control，and quantification of storage efficiency and leakage risks，SC-CO₂ fracturing shows strong potential for the integrated development pathway of fracturing，enhanced recovery and carbon sequestration in unconventional reservoirs.