Abstract: In order to efficiently enrich IgG, reduce waste of bovine colostrum and improve the product value, the combined microfiltration-ultrafiltration technology was used to enrich IgG in bovine colostrum whey. First, the application of microfiltration technology in the sterilization of bovine colostrum whey was studied, and its operation process was optimized. Second, bovine colostrum whey after microfiltration sterilization was enriched by ultrafiltration technology, on the basis of single factor experiment, the ultrafiltration process was optimized by response surface, and the quality of enriched bovine colostrum whey was analyzed. The results showed that the best process parameters of bovine colostrum whey microfiltration were: Microfiltration pressure was 0.2 MPa, temperature was 30 ℃, the best process parameters of ultrafiltration enrichment were: Ultrafiltration pressure was 0.15 MPa, temperature was 35 ℃, concentration multiple was 6 times and dilution times was 4 times. According to these conditions, microfiltration-ultrafiltration operation of bovine colostrum whey was carried out, IgG concentration rate was 58.19%, and the membrane flux was 204.46 L/m²·h. The quality analysis of enriched bovine colostrum whey showed: The IgG content was 22760 µg/mL, IgG activity was 718.31 IU/L, protein content was 7.86%, fat content was 0.035%, and the total number of colonies was 2.4 lg CFU/ mL. This study provides a reference for further development and comprehensive utilization of IgG in bovine colostrum whey.