The invention belongs to the field of medicine and specifically relates to application of xanthohumol in an aspect of preparing a protein kinase B inhibitor. A molecular formula of the xanthohumol is C21H22O5, and a molecular weight of the xanthohumol is 354.4. Experiments show that the xanthohumol can inhibit tumor growth through an inhibition effect on the protein kinase B (AKT). The application disclosed by the invention verifies that the xanthohumol can inhibit kinase activity of the protein kinase B, inhibit proliferation of esophageal squamous carcinoma cells of KYSE70, KYSE450 and KYSE 510 and inhibit growth of esophagus cancer patient-derived xenograft model (PDX) tumor; thus, the xanthohumol is shown to have an obvious inhibition effect of tumor. The xanthohumol can serve as the protein kinase B inhibitor to be applied to preventing and treating varieties of tumors of esophagus cancer, lung cancer, gastric cancer, colon cancer, liver cancer, breast cancer and the like.