Abstract: Cold pressing combined with supercritical CO₂ extraction (CP-SCB) could effectively reduce the residual oil content of walnut meal; However, its effects on the nutritional value and functional properties of walnut meal protein remain unclear. In this study, the effects of cold pressing (CP) and CP-SCB on the nutritional composition, structural characteristics, and functional properties of walnut meal protein were comparatively evaluated. The results showed that CP-SCB reduced the fat content of walnut meal from 20.50% to 0.40% and increased the protein content by 15.50%, reaching a protein purity of 67.90%. The ratios of essential amino acids to total amino acids (EAA/TAA) of walnut meal proteins obtained by the two processes were both close to 28%, and their amino acid scores were comparable. However, CP-SCB treatment led to decreases of 2.53% and 4.51% in α-helix and β-sheet contents, respectively, indicating an increase in molecular conformational flexibility. Scanning electron microscopy revealed that CP-derived proteins mainly consisted of relatively dense, large spherical aggregates with surface depressions, whereas CP-SCB-derived proteins exhibited fragmented, loose, and irregular aggregate structures. Compared with CP samples, CP-SCB proteins showed reduced foaming capacity in the pH range of 6.0~8.0, while only minor differences in foam stability were observed between the two samples. Although the emulsifying activity of the two proteins was comparable, CP-SCB exhibited higher emulsion stability at pH8.0. These results provide a scientific basis for the application and promotion of CP-SCB technology in the integrated production of walnut oil and walnut meal protein.