A multifunctional immunity-targeted micromolecule anti-cancer medicine Bestazomib and preparation method and application thereof. The structure of the multifunctional immunity-targeted micromolecule anti-cancer medicine Bestazomib is shown as follows : the multifunctional immunity-targeted micromolecule anti-cancer medicine Bestazomib has an activity-inhibiting effect on APN/CD13, also has an activity-inhibiting effect on tumor proteasome, and can be applied to the development of medicines for treating malignant tumors.