Abstract: Objective: High-purity retinol-binding protein 4 (RBP4) monoclonal antibody was prepared and used to detect the expression level of RBP4 in a mouse liver cancer model transfected with high-pressure hydrodynamics. Methods: The recombinant RBP4 protein-expressing bacterial strain was cultured, and the RBP4 protein was induced to express and purified using the AKTA system.High-purity RBP4 monoclonal antibodies were prepared through hybridoma technology. The 7-week-old SPF grade C57BL/6J mice were randomly divided into experimental and control groups, with 6 mice in each group, and evenly split between male and female. High-pressure hydrodynamic transfection combined with the SB11 transposon system and the CRISPR/Cas9 system was used to construct a liver cancer model in the experimental group of mice.RBP4 monoclonal antibody was used to detect the expression level of RBP4 in liver cancer mouse model by immunohistochemistry. Results: The recombinant RBP4 protein with a purity of more than 95% was successfully obtained. In the process of preparing RBP4 monoclonal antibody, the hybridoma cell fusion rate was 60%. Finally, 3 positive monoclonal cell lines were obtained, and the monoclonal antibody with high efficiency (1:243000) and high purity (96.77%) was purified. The high-pressure hydrodynamic transfection mouse model of liver cancer was successfully established, with a 100% incidence rate of liver cancer in the experimental group. The liver tissues exhibited typical pathological characteristics of liver cancer, while no liver cancer was observed in the control group. Immunohistochemical detection of RBP4 monoclonal antibody showed that the expression level of RBP4 in the liver cancer tissues of the experimental group was significantly lower than that of the control group (P< 0.001). Conclusion: The RBP4 monoclonal antibody prepared in this study has the characteristics of high efficiency and high purity, and the expression level of RBP4 protein is significantly decreased in the liver cancer tissues of mice with high-pressure hydrodynamic transfection. Further research is warranted to investigate the relationship between RBP4 and the occurrence and development of liver cancer.