Provided are a composite carrier for immobilization of a protein, polypeptide or oligopeptide, a preparation method and an application thereof. The composite carrier is a porous material which comprises: (1) a porous organic foam material containing open pores； and (2) a crosslinked product having aldehyde groups and immobilized on the surface of the walls of one or more pores of the porous organic foam material, wherein the aldehyde groups are able to react with the protein, polypeptide or oligopeptide, and the crosslinked product are formed by chitosan via a crosslinking reaction with a polyaldehyde compound.
