A new core-shell structured nanomaterial based on Fe3O4 nanoparticles and 2,3-dialdehyde nanocrystalline cellulose (DAC) coating and its high efficiency in the preconcentration of glycoproteins were described in this work. DAC was obtained after the periodate oxidation of nanocrystalline cellulose to form aldehyde groups; then, Fe3O4 nanoparticles were coated with DAC, which were further attached to 4-aminophenylboronic acid (PBA) to form PBA-functionalized magnetic core-shell structured materials (Fe3O4@DAC-PBA). The oxidation of cellulose and the production of sufficient amounts of aldehyde group sites were essential for the preparation of Fe3O4@DAC-PBA used for the affinity adsorption of glycoproteins because the aldehyde groups on DAC allowed DAC to attach to the Fe3O4 nanoparticles and bind with PBA, which was active in forming a complex with the glyco sites in glycoproteins. Moreover, the preconcentration properties of Fe3O4@DAC-PBA through PBA adsorption can be pH-triggered without the disassembly of the structures; thus, the developed Fe3O4@DAC-PBA can be efficiently prepared to provide a promising affinity material for the affinity adsorption and purification of glycoproteins.